OBJECTIVES: It is important to be able to detect symptoms of common mental disorders (CMDs) in pregnant women. However, the expression of these disorders can differ across cultures and depend on the specific scale used. This study aimed to (a) compare Gambian pregnant women's responses to the Edinburgh Postnatal Depression Scale (EPDS) and Self-reporting Questionnaire (SRQ-20) and (b) compare responses to the EPDS in pregnant women in The Gambia and UK. DESIGN: This cross-sectional comparison study investigates Gambian EPDS and SRQ-20 scores through correlation between the two scales, score distributions, proportion of women with high levels of symptoms, and descriptive item analysis. Comparisons between the UK and Gambian EPDS scores were made by investigating score distributions, proportion of women with high levels of symptoms, and descriptive item analysis. SETTING: This study took place in The Gambia, West Africa and London, UK. PARTICIPANTS: 221 pregnant women from The Gambia completed both the SRQ-20 and the EPDS; 368 pregnant women from the UK completed the EPDS. RESULTS: Gambian participants' EPDS and SRQ-20 scores were significantly moderately correlated (rs=0.6, p<0.001), had different distributions, 54% overall agreement, and different proportions of women identified as having high levels of symptoms (SRQ-20=42% vs EPDS=5% using highest cut-off score). UK participants had higher EPDS scores (M=6.5, 95% CI (6.1 to 6.9)) than Gambian participants (M=4.4, 95% CI (3.9 to 4.9)) (p<0.001, 95% CIs (-3.0 to -1.0), Cliff's delta = -0.3). CONCLUSIONS: The differences in scores from Gambian pregnant women to the EPDS and SRQ-20 and the different EPDS responses between pregnant women in the UK and The Gambia further emphasise how methods and understanding around measuring perinatal mental health symptoms developed in Western countries need to be applied with care in other cultures.Cite Now.