Sperm precedence, defined as nonrandom differential fertilization success among mating males, is an important postmating component of sexual selection. This study examined the relationship between premating and postmating components of sexual selection in males of the flour beetle (Tribolium castanewn). Male olfactory attractiveness to females was positively correlated with a male's subsequent fertilization success: more attractive males achieved higher second-male sperm precedence when allowed to mate with previously inseminated females. Attractive males may achieve compounded gains in their reproductive success through enhanced mating opportunities as well as through greater fertilization success. Thus, the relationship between these reproductive fitness components may augment differences in reproductive success among males. Female fecundity, estimated as the number of adult progeny produced, increased significantly with multiple malings. This result supports increased female reproductive success as a direct benefit of multiple mating in T. caslaneum and suggests that progeny production is partially limited by sperm availability. Total progeny production by doubly mated females remained constant at all levels of second-male sperm precedence. However, higher sperm precedence was associated with a decline in firstmale progeny and a concomitant increase in second-male progeny. This pattern of progeny production suggests that more attractive males may achieve higher fertilization success through a combination of displacement of previously stored sperm, transfer of greater sperm quantities, or females' preferential use of sperm of attractive males for fertilizations. © 1994 International Society for Behavioral Ecology.