Common mental disorders are highly prevalent in emergency centre (EC) patients, yet few brief screening tools have been validated for low- and middle-income country (LMIC) ECs. This study explored the psychometric properties of the SRQ-20 screening tool in South African ECs using the Mini Neuropsychiatric Interview (MINI) as the gold standard comparison tool. Patients ( n  = 200) from two ECs in Cape Town, South Africa were interviewed using the SRQ-20 and the MINI. Internal consistency, screening properties and factorial validity were examined. The SRQ-20 was effective in identifying participants with major depression, anxiety disorders or suicidality and displayed good internal consistency. The optimal cutoff scores were 4/5 and 6/7 for men and women respectively. The factor structure differed by gender. The SRQ-20 is a useful tool for EC settings in South Africa and holds promise for task-shifted approaches to decreasing the LMIC burden of mental disorders.