BackgroundTo combat the increasing rate of suicide, basic data on suicidal behaviours reflecting the uniqueness of the locality are needed in sub-Saharan Africa.AimsTo assess the prevalence of suicidal ideation and associated factors.MethodAdults (n=11 246) from the five administrative divisions of Lagos State completed questionnaires detailing suicidal ideation, socio-demographic details, common mental disorders (depression, anxiety and somatic symptoms), alcohol and psychoactive substance use disorders and disability.ResultsThe weighted prevalence of current suicidal ideation was 7.28% (s.e. 0.27). Independently associated factors were older age, being female, not married, low occupational group, depression, anxiety, somatic symptoms and disability.ConclusionsDespite the validity of cross-national surveys, there is need for individual countries to generate complementary local data to explain variability in rates and risk factors in order to plan for suicide prevention or develop timely and effective response.