Poupakis first came up with Aegaleo. In 1974, he first transferred to Olympiakos. He remained with the Piraeus club until the 1979 season when he joined OFI. After three years with the Cretan club he left for Panathinaikos (1982). Poupakis returned to Olympiakos in 1983 as a backup keeper for Nikos Sarganis but in the following year transferred to Apollon Athens, his final club.
He was capped 6 times by the Greek National Football Team.