In retirement, Viola coached baseball for Lake Highland Preparatory School for a time in Orlando, Florida. He also coached with the Florida College Summer League's Leesburg Lightning. In 2009, Viola assisted the Cleveland Indians as a coach in spring training. Frank was also a part-time, substitute game broadcast announcer for NESN, network of the Boston Red Sox. On January 26, 2011, Viola was hired as pitching coach of the Brooklyn Cyclones, the Mets' Single-A (Short Season) team. Viola spent 2012–2013 as the Single-A Affiliate Savannah Sand Gnats pitching coach, winning Coach of the Year in 2013. Following the season, Viola was named the pitching coach for the Las Vegas 51s, the Mets' Triple-A affiliate in the Pacific Coast League. During a 2014 spring training physical, Viola was diagnosed with a heart condition that required open-heart surgery on April 2. After surgery he signed with Las Vegas 51s.