Objective: Examine the longitudinal association of generational status (first = child and parent born outside the United States; second = child born in the United States, parent born outside the United States; third = child and parent born in the United States) and parent and peer social factors considered in 5th grade with subsequent oral, vaginal, and anal intercourse initiation by 7th and 10th grade among Latino/a youth. Method: Using data from Latino/a participants (N = 1,790) in the Healthy Passages™ study, the authors measured generational status (first = 18.4%, second = 57.3%, third-generation = 24.3%) and parental (i.e., monitoring, involvement, nurturance) and peer (i.e., friendship quality, social interaction, peer norms) influences in 5th grade and oral, vaginal, and anal intercourse initiation by 7th and 10th (retention = 89%) grade. Results: Among girls, parental monitoring, social interaction, friendship quality, and peer norms predicted sexual initiation. Among boys, parental involvement, social interaction, and peer norms predicted sexual initiation (ps < .05). When ≥1 friend was perceived to have initiated sexual intercourse, third-generation Latinas were more than twice as likely as first- and second-generation Latinas (ps < .05) to initiate vaginal intercourse by 10th grade and almost 5 times as likely as first-generation Latinas to initiate oral intercourse by 7th grade. Conclusions: Among Latina youth, generational status play a role in social influences on vaginal and oral intercourse initiation. Moreover, Latinas and Latinos differ in which social influences predict sexual intercourse initiation. Preventive efforts for Latino/a youth may need to differ by gender and generational status.