Peterka made his World Cup debut on 4 January 1996. Due to the poor performance of Slovenian jumpers at the time, Peterka was brought in as a replacement for the Four Hills Tournament event in Innsbruck, where he finished eighth. This was considered a superb result, thereby making him the leading jumper for Slovenia. Peterka continued his good form, winning the events in Zakopane and Falun, and finishing the season ninth overall. He also finished second behind Michael Uhrmann at the 1996 Junior World Championships.
1996–1997
The 1996/97 season was a great success for Peterka. He won seven individual World Cup events, and the Four Hills Tournament. Peterka dominated the overall World Cup standings as only one competitor finished within 200 points. Peterka finished on top the ski flying standings. On 9 February 1997, Peterka became the first Slovenian to record a jump over 200 metres, landing a 203 m jump at Kulm.
1997–98
The 1997/98 season was also successful. Peterka won four individual events and a second consecutive World Cup title, defeating Kazuyoshi Funaki in the final event of the season. At the 1998 Winter Olympics in Nagano, Peterka claimed fifth place in the individual large hill event and sixth in the individual normal hill event.
Later career
Peterka underwent a personality crisis after his success, with significant drop in results. During this time, details of his personal life were discussed in public, mostly his clashes with officials and his relationship with Renata Bohinc, a Slovenian beauty queen who won in 1996. A turning point in Peterka's life and career came in 2001 when his son was born. In the 2001/02 World Cup season, Peterka returned to the ski jumping elite. At the 2002 Winter Olympics in Salt Lake City, he won the bronze team medal. The 2002/03 season was also successful, with Peterka winning two individual events and finishing the season seventh overall. From 2004 onwards, Peterka never again managed to finish in the top 10 in an individual World Cup event. However, at the 2005 World Championships in Oberstdorf he won another bronze team medal for Slovenia, together with Jure Bogataj, Rok Benkovič and Jernej Damjan. This made Peterka the first Slovenian ski jumper to win medals both at the Olympics and at the World Championships. After the 2010/11 season, Peterka officially retired from competitive ski jumping.
Film
Three sports documentary films were made about his life and career. The first was called Vleci, Primož and was directed by Beno Hvala in 1997, detailing the story of Peterka's early career. The second, Peterka: leto odločitve, was directed by Vlado Škafar in 2002 and focuses on the personality crisis of a young champion who struggles to find his way back to the top. The third one was made in 2011 for TV Slovenia, called Skoki so moje življenje, directed by Tomaž Kovšca. Screenplay by Aleš Potočnik and Polona Bertoncelj.
