Johnny Galecki Leonard Hofstadter Actor Jim Parsons Sheldon Cooper Actor Kaley Cuoco Penny Actor Simon Helberg Howard Wolowitz Actor Kunal Nayyar Raj Koothrappali Actor Mark Harelik Dr. Eric Gablehauser Guest Star Charlie Sheen Charlie Sheen Guest Star Brian George Dr. V.M. Koothrappali Guest Star Alice Amter Mrs. Koothrappali Guest Star Chuck Lorre Executive Producer, Writer Bill Prady Executive Producer, Writer Stephen Engel Writer Tim Doyle Writer Mark Cendrowski Director