Yes. A batter is credited with at least one RBI (run batted in) when he hits a home run. He is also credited with a run scored when he crosses home plate.

If there are men on base ahead of him, then the batter who hits a home run is also credited an RBI for each of those runners who score. All told here is the number of runs batted in credited to a batter who hits a home run with a specific number of runners on base ahead of him:

Number of Men on Base RBI for Batter Hitting Home Run
0 1
1 2
2 3
3 4
RBI credited to batter who hits a home run

A bases-loaded home run (one with three men already on base) is a Grand Slam!