Objective: To determine the characteristics of depressed older patients whose mental health status is detected by their general practitioner (GP).Method: Cross-sectional analytical design of 218 patients scoring above the cut-off (>= 16) of the Center for Epidemiological Studies - Depression Scale (CES-D), from a sample of 916 consecutive patients aged 60 years or over attending one of 54 randomly selected GPs in Western Australia. Prior to their medical consultation, patients completed a self-report questionnaire, which included questions about depressive symptomatology (CES-D). Following the consultation, general practitioners recorded the patient's presenting complaint(s), medication information, and mental health details on a patient summary sheet.Results: Among these 218 patients, 39.9% (87/218) were correctly classified as depressed by their GP. Detection of depressive symptomatology was associated with patients who acknowledged taking sleeping tablets (OR = 2.6, 95% CI = 1.3-5.4), had CES-D scores indicative of major depression (>= 22) (OR = 2.8, 95% CI = 1.4-5.6) and were thought to be at risk for suicide (OR = 35.1, 95% CI = 4.5-274.2).Conclusions: While GPs are most apt to detect depression among older patients with prominent mental health symptoms, many patients in this age group silently experience significant depressive symptomatology and miss the opportunity for effective treatment. The routine use of screening tools in primary care is recommended to enhance the detection rate of depression in older adults.