We investigated point defects and dopant atoms in (11 (2) over bar 0) and (10 (1) over bar 0) cleavage surfaces of CdSe using atomically resolved scanning tunneling microscopy images. Positively charged dopant atoms give rise to elevations of up to 5 nm in diameter in the empty and occupied state images. Uncharged Se and Cd Vacancies exhibit an isolated missing occupied and empty dangling bond, respectively. In CdS (10 (1) over bar 0) surfaces we observed In dopant atoms and accepters. On the basis of the observed defects and dopant atoms and their concentrations the origin of the electrical compensation is discussed.