Aim: To assess the prevalence and associated factors of suicidal behaviour (suicidal ideation, plan or suicide attempt) in postpartum mothers.

Method: An institutional cross-sectional study was employed from March to April 2017.

Setting: Two primary health centres and one referral hospital in northwestern Ethiopia.

Participants: A total of 1065 mothers aged ≥18 years during routine postnatal care were included and 988 of them completed the study. Those who were unable to communicate due to illness were not included.

Outcome measure: Mothers who visit for routine postnatal care were assessed for suicidal behaviour using a suicidal screening tool. Logistic analysis was employed with adjusted OR (AOR) and 95% CI, and with p value less than 0.05 as the level of significance.

Results: The prevalence of suicidal behaviour (suicidal ideation, plan or suicide attempt) was found at 14.0% (138/988) (95% CI 12.00 to 16.00) in postpartum mothers. Poor wealth of the mother (AOR=2.80, 95% CI 1.18 to 6.84), unplanned pregnancy of the current child (AOR=2.28, 95% CI 1.48 to 3.54), history of rape (AOR=2.26, 95% CI 1.42 to 3.61) and sickness of the new child (AOR=1.68, 95% CI 1.12 to 2.52) were significantly associated with suicidal behaviours.

Conclusion: Suicidal behaviour was found pretty high among postpartum mothers and was associated with poor wealth, unplanned pregnancy, history of rape and sickness of the new infant. It is recommended to screen mothers for possible suicidal behaviour during routine postnatal care.