This study reports an ethnobotanical survey by means of semi-structured questionnaire of medicinal plants in five districts of Lagos State of Nigeria reputed for the treatment of diabetes. 100 respondents from the predominantly Yoruba tribe mostly males (76%) were knowledgeable in traditional treatment of diabetes. About half of the respondents with 20-30 years experience in treating diabetes used mainly herbs (96%) and have developed effective and easily recognised diagnostic tools. 92% of diabetic patients were usually out-patients aged 21-60 years. Diabetes trado-specialists (80%) rarely referred their patients but usually treated referred cases (96%). Fifty multi-component herbal recipes covered in the survey were mainly liquid preparations often administered without serious side effects (92%). The principal antidiabetic plants included Vernonia amygdalina, Bidens pilosa, Carica papaya, Citrus aurantiifolia, Ocimum gratissimum, Momordica charantia and Morinda lucida. Dietary recommendations also accompanied therapy.