Objective: Early life exposure to anesthesia and surgery is suspected to associate with cognitive impairment later in life. We compared academic achievement among adolescents with cleft lip only (CL), cleft palate only (CP), and cleft lip and cleft palate (CLP) with a noncleft control group to investigate whether outcome depends on timing and number of operations during childhood and/or type of oral cleft. Design: Nationwide register-based follow-up study. Setting: Danish birth cohort 1986 to 1990. Participants: Five hundred fifty-eight children with isolated CL (n = 171), CLP (n = 222), or CP (n = 195), of which 509 children had been exposed to anesthesia and one or more cleft operation(s), and a 5% sample of the birth cohort (n = 14,677). Main Outcome Measure(s): Test score in the Danish standardized ninth-grade exam and proportion of nonattainment, defined as "results for ninth-grade exam unavailable." Data adjusted for sex, birth weight, parental age, and parental level of education. Results: Compared to controls, children with CL achieved higher scores (mean difference 0.12, 95% CI -0.05; 0.29) and children with CLP presented with lower scores (mean difference -0.06, 95% CI -0.21; 0.09), albeit both statistically insignificant. Children with CP achieved significantly lower scores, mean difference -0.20 (95% CI -0.38; -0.03). Odds ratios for nonattainment at final exam were: CL 0.79 (95% CI 0.46; 1.35), CLP 1.07 (95% CI 0.71; 1.61), CP 2.59 (95% CI 1.78; 3.76). Conclusions: Oral cleft type rather than number and timing of anesthesia and operations associate to poorer academic performance. Although a potential neurotoxic effect due to anesthetic agents is not reflected in the data, it cannot be completely excluded.