The adult potato tuberworm, Phthorimaea operculella (Zeller), is a primary pest of potato plants. Studies were conducted to assess the possibility of applying sterile insect technique as an alternative control method against this pest. The purpose of this study was to examine the effects of adult age, weight, female mating status, and sex ratio on success and frequency of mating in P. operculella. The relationship between number of matings, fecundity, and fertility of females was also studied. A negative correlation was found between mating success and adult age. Female and male weights had an effect on the number of times individuals mate, but male weight only influenced mating success. Males mated more than once when confined with three virgin females for 24 h. Females did not mate more than once, even when they were confined with three virgin males. Males were more likely to mate with virgin females than with previously mated females. Multiply mated females and those which did not accept a second mating showed higher fecundity and fertility than their counterparts which were not given the opportunity to remate. Our results provide essential information necessary to increase the effectiveness of sterile insect technique as a control method against P. operculella.