Mike Rostenkowski (Casey Sander) is Bernadette's father and a retired police officer. Mike has a rough and rude personality and often bullies others, although he deeply loves his daughter, calling Bernadette his "little girl". Before he is first seen, Bernadette establishes his personality by telling Howard a long list of subjects he cannot discuss with Mike, including Jimmy Carter, foreigners, homosexuals, and even Howard's Jewish identity. Mike oddly enough gets on very well with Sheldon, filling a role in his life vacated by his deceased father, George.