This study assessed whether trajectories of parental monitoring components were different for sexual minority girls (SMGs) compared to heterosexual girls. We recruited 14–19‐year‐old girls from two adolescent medicine clinics. We estimated growth curve models to compare how components of parental monitoring—adolescent disclosure, parental solicitation, and parental knowledge—changed over 2 years for SMGs and heterosexual girls. SMGs and heterosexual girls had similar trajectory slopes and quadratic forms of adolescent disclosure, but SMGs had consistently lower adolescent disclosure scores. Parental knowledge trajectories indicated differential intercepts and slopes for SMGs compared to heterosexual girls, suggesting potential higher risk for maladaptive behaviors. Results of this study suggest that parental monitoring may operate differently over time for SMGs compared to heterosexual girls.