Career
He began his career in 1989 with Kansas Lublinianka. In 1998 he moved to Viborg FF from Widzew Łódź and established himself as Viborg"s number one goalkeeper. In 2003 he transferred to Odense Boldklub, where he spent the next six years as OB"s first choice goalkeeper.
Between 1998 and 2009 he played 363 games in the Danish Superliga, which makes him the 5th most capped player and the most capped foreigner.
After a turbulent time in Denmark, Onyszko returned to Poland and on 13 January 2010 signed a short-term contract with Odra Wodzislaw. The club came last in the league this season and were relegated, but Onyszko"s displays were impressive enough to earn him a 2-year contract with Polonia Warsaw, which he signed in May 2010.
However, in June 2010 Onyszko was diagnosed with a kidney failure, and as of late 2010 his career is on hold while he is awaiting a transplant. His club fired him the very same day.
A few days later he signed a contract with Danish club Football Club Midtjylland.
- He was fired on 2 November for issuing a book containing verbal attacks on homosexuals and female sport reporters. In his native Poland he was criticised for his anti-gay statements and sparkling anti-polish sentiment. His remarks were named as an example of homophobia in sport.
His controversies were acknowledged as shameful to Poland and his book a disgrace, being more popular than Nobel Prize–winning Polish literature.