Patients with a range of medical disorders, including diabetes mellitus, are increasingly seeking access to assisted reproductive technology (ART). With appropriate patient selection, monitoring and counselling, these technologies may be applied successfully. Diabetes in the female is associated with disturbed ovarian function but strict metabolic control may encourage resumption of ovulation and allow ovarian stimulation for ART. Insulin metabolism appears intimately involved with ovarian function, through mechanisms encompassing the actions of insulin-like growth factors, but is not yet fully understood. Diabetes has minimal effects on spermatogenesis but may severely disrupt erectile and/or ejaculatory function; the techniques of epididymal sperm aspiration and intracytoplasmic sperm injection (ICSI) are particularly useful in such cases. Well-controlled diabetes is not associated with recurrent miscarriage but diabetes is a risk factor for pregnancy-induced hypertension and, poorly controlled, is associated with neonatal macrosomia. In reproduction, as in general health, good metabolic control is key to a successful outcome.