Aims: To estimate the 12-month prevalence of DSM-IV-specific anxiety disorders among Nigerian secondary school adolescents aged 13-18 years. Method: A representative sample of adolescents (n=1090) from senior secondary schools in a semi-urban town in Nigeria was assessed for the 12-month prevalence of DSM-IV-specific anxiety. Results: The 12-month prevalence for all anxiety disorders was 15.0% (females=19.6%; males=11.4%). There were significant gender differences in the prevalence for all anxiety disorders (P less than 0.001; OR 1.96, 95% CI 1.35-2.65) and social anxiety disorder (P=0.035; OR 1.82, 95% CI 1.03-3.19) and significant age difference in the prevalence of separation anxiety disorder (P=0.045; OR 2.43, 95% CI 0.99-5.96). Conclusion: The prevalence of anxiety disorders in Nigerian secondary school adolescents was comparable to the rates found in the western world. Health policies must integrate adolescents' anxiety as a disorder of public health significance. Further studies are needed to evaluate the factors associated with anxiety disorders amongst adolescents in this region.