He played junior hockey for the Toronto Marlboroughs of the OHL and was drafted in 1978 NHL Amateur Draft by the Atlanta Flames. Peplinski was one of five active NHL players who played on Canada's 1988 Olympic ice hockey team. In 1989 he co-captained the Calgary Flames in their Stanley Cup victory against the Montreal Canadiens.
Peplinski retired early in the 1989–90 NHL season, and then began a career in broadcasting. In 1995, he stepped out of the booth and briefly returned to play for the Flames, before retiring again at the end of the season. He has since forged a successful business career in the Calgary area.
Peplinski is the Executive Chairman, Humberview Group of Companies which owns Jim Peplinski’s Leasemaster, nine automotive dealerships in Toronto and various real estate investments. He is also the VP Business Development, Calgary Flames Hockey Club as well as an investor and director of Wrangler West Energy Corp., a public oil and gas company.