OBJECTIVES: To evaluate use of a single-tablet (levonorgestrel 1.5 mg) emergency contraceptive administered to young females under simulated over-the-counter conditions. Secondary objectives were to assess repeat use, pregnancy, and adverse events. METHODS: Females aged 11-17 years requesting emergency contraception at teen reproductive health clinics in five cities were eligible to participate. Participants read the study product label and determined whether and how to use the product without interacting with providers. Study product was dispensed to participants who appropriately selected to use it; participants were contacted 1, 4, and 8 weeks later to assess use, pregnancy, and adverse events. The incidences of outcomes were calculated and regression analysis was used to assess the effect of age and use status (ever used or no previous use) on primary outcomes. RESULTS: Of the 345 females enrolled, 279 were younger than age 17 years. Among the 340 participants included in the selection analysis, 311 (91.5%) (97.5% confidence interval 87.5- 94.5%) participants appropriately selected to use or not use product. Among the 298 participants who used product, 274 (92.9%) (97.5% confidence interval 88.8-95.8%) correctly used it as labeled. Selection and correct use were not associated with age. Fifty-seven participants (18.8%) used additional emergency contraception over the study period and seven (2.3%) participants who used product became pregnant; there were no unusual adverse events. CONCLUSION: Restricting young females’ use of a single-tablet emergency contraceptive by prescription only is not warranted, because females younger than 17 years can use it in a manner consistent with over-the-counter access. LEVEL OF EVIDENCE: II.