This study examined how parent-child communication regarding adolescent unsupervised activities develops over the course of adolescence. We used questionnaire data from 390 adolescents (58% girls; 90% European Canadian) who were followed from age 12 to 19. Latent growth curve modeling revealed curvilinear developmental changes that differed for boys and girls. From age 14 to 19 (but not from age 12 to 14) a linear decrease in parental control was found for both genders. For girls, parent-child communication decreased in early adolescence, as indicated by decreasing parental solicitation, decreasing adolescent disclosure, and increasing secrecy. Girls' communication with parents intensified in middle adolescence, as indicated by increasing parental solicitation, increasing adolescent disclosure, and decreasing adolescent secrecy. For boys, disclosure declined in early adolescence, but secrecy and solicitation were stable throughout adolescence. Parental knowledge decreased from age 12 to 19 for both genders but was temporarily stable for middle adolescent girls. The meaning of these developmental changes, their timing, and gender differences are discussed.