In 2005, he became Director of the Wrocław Philharmonic and the International Festival Wratislavia Cantans – he led to a change of the profile of both institutions and to transforming them into the National Forum of Music. The opening of the new venue of the National Forum of Music, which was established thanks to his initiative and efforts, was awarded with the Coryphaeus of Polish Music 2016 in the Event of the Year category. Andrzej Kosendiak was Chairman of the Board of the Society of Polish Philharmonics for three terms, he was Deputy Chairman of the Council for Artistic Institutions at the Ministry of Culture and National Heritage (2016-2019), he was a member of the Music Programme Council of the National Institute of Music and Dance, and from 2021 has been a member of the University Council of the University of Economics in Wrocław.
As the director of the Wrocław Philharmonic, he established new ensembles, including the NFM Choir, Wrocław Baroque Orchestra and the NFM Boys' Choir, and also initiated the Leo Festival and Forum Musicum. Moreover, he was one of the co-authors of Muzyka w Mieście monthly, published from 2012–2018 by the National Forum of Music. Early music is of particular interest to Andrzej Kosendiak. In 1985, he founded the Collegio di Musica Sacra ensemble, and in 2013 – the Wrocław Baroque Ensemble of which he is Artistic Director. Andrzej Kosendiak regularly conducts philharmonic orchestras in Poland and abroad. He has performed in many European countries, the United States (including collaboration with the University of North Carolina at Chapel Hill) and China.

He is extremely active in the field of education. In the years 1990–2000 he was an inspector of the Centre for Artistic Education, and in the years 2000–2001 he was Director of the Department of Programming and Supervision of Artistic Education at the Ministry of Culture and National Heritage. He initiated such educational projects as Singing Wrocław, Singing Poland, international meetings of Singing Europe choirs, Mummy, Daddy, Sing to Me. Thanks to his support, the following were established: the Polish National Youth Choir, the Choir Academy, the Early Music Academy (an annual festival combining master classes with concerts), the Orchestral Academy (preparing musicians to work in professional ensembles), and the NFM Education Centre. He was the originator of the Musica polonica rediviva programme, the aim of which is encouraging performances of Polish music by young artists around the world with the support of conservatories and festivals (so far the programme has been implemented in cooperation with the Koninklijk Conservatorium in The Hague, Conservatorio di Musica Luca Marenzio in Brescia and Conservatorio Superior de Música de Aragón in Zaragoza).
 
Andrzej Kosendiak has initiated a series of albums 1000 Years of Music in Wrocław and Witold Lutosławski. Opera omnia. Thanks to his efforts, a joint phonographic project by Paul McCreesh and the NFM Choir is being carried out, including recordings of great oratorios. The albums released so far have won the BBC Music Magazine Award twice, a Diapason d'Or and a Gramophone's Editor's Choice. He has recorded previously unknown works from the University Library in Wrocław and the library in Strasbourg (Wrocław Music Prize – Music Event of the Year 2000 for the album Musica da Chiesa), compositions by Grzegorz Gerwazy Gorczycki (Wrocław Music Prize2013), Bartłomiej Pękiel and Marcin Mielczewski; most of these recordings were nominated for the Fryderyk award, and in 2019 a Fryderyk was won by the album Mielczewski II (Album of the Year - Early Music). In 2018, a CD with Stanisław Moniuszko’s Phantoms was released, conducted by Andrzej Kosendiak - recorded by excellent singers and actors, the NFM Choir and Wrocław Baroque Orchestra; it received a Fryderyk 2019 (Album of the Year – Choral, Oratorio and Opera Music). Albums of A.M. Bononcini: La decollazione di San Giovanni Battista with Wrocław Baroque Orchestra and Mikołaj Zieleński: Offertoria et communiones totius anni with Wrocław Baroque Ensemble – both recorded under the baton of Andrzej Kosendiak – were nominated in the Baroque Vocal category for the International Classical Music Awards in 2020 and 2021, respectively. Recently, new albums with old Polish music were released – with compositions by Stanisław Sylwester Szarzyński, Mikołaj Zieleński and Jacek Różycki. The CD with Zieleński’s compositions was awarded a Fryderyk 2021 (Album of the Year – Early Music).

Andrzej Kosendiak has received numerous awards and distinctions, including: Tulips of the National Life Day in the Social Initiative category (2011) for the project Mummy, Daddy, Sing to Me, Award of the President of Wrocław (2016), Lower Silesian Key of Success in the category of the Greatest Personality in the Promotion of the Region (2016), Radio Wrocław Kultura – Emotions awards in the categories of Personality of the Cultural Season (2017) and Classical Music (2018), Austrian Honorary Cross of 1st Class for Merit in Science and Arts (2018), Wrocław Diamond (2018), Golden Badge of Honour Meritorious for the Lower Silesian Voivodeship (2018), the award of the College of Rectors of Universities in Wrocław and Opole for activities for the integration of the academic community (2019), the Golden Honorary Badge of Wrocław “Wrocław with gratitude - Wratislavia grato animo” (2020), and for merits in popularising culture and service to artistic education and music development, he was awarded the Officer’s Cross of the Order of Polonia Restituta (2023).