Tasaduq, a famed cinematographer, joined the party in the presence of his sister and Chief Minister Mehbooba Mufti who was there along with her cabinet and party colleagues.
In his brief speech at the function, Tasaduq thanked the party workers for their love and affection towards PDP.
"I have remained aloof from politics all my life. But today I have joined the PDP officially and it is a very important day of my life. I will walk with you and take your aspirations along," he told the party men.
He said his dream was to clean up politics in Kashmir.
"I have felt the pace of government work. The speed with which work happens here, what dream can be realised?" he asked.
Welcoming her brother into the party fold, Mehbooba said Tasaduq -- like his father, the late Mufti Mohammad Sayeed -- has a dream to do something for Jammu and Kashmir.
"Tasaduq has his own identity and his own work. No one in Mumbai knew him as Mufti Sayeed's son till his second term (as chief minister). Like his father, he wants to do something for Jammu and Kashmir," she said in her address.
Known for his cinematography in movies like Omkara and Kaminey, Tasaduq is an American Film Institute graduate.
He is known in Bollywood as Tassaduq Hussain and does not use the famous Mufti surname.