In 2005, Muthiya turned professional. In 2006, he had many highlights. In March, he finished second at the
Zambia Open. He joined the
Canadian Tour later in the year. In the summer he also became the first Zambian and black African to play in the
U.S. Open. He missed the cut at the
2006 U.S. Open. He played on the
Nationwide Tour in 2010 where his best finish was T-7 at the
Mylan Classic. In July 2016, he won his first
Sunshine Tour title in a
Vodacom Origins of Golf Tour event, the first Zambian to win on the Sunshine Tour and only the fourth black African. In 2018, he won the Ivory Coast Open with a score of 18-under-par, setting the course record. ==Professional wins (2)==