The annual pilgrimage to Makkah (Mecca), Hajj, is a very stressful endeavour and requires strenuous physical effort, especially for the diabetic, the elderly and persons with other chronic illnesses. To identify the complications and to assess the needs of the Omani diabetics during Hajj (DOH), a special diabetes clinic was established in the camping site of Omani pilgrims (Hajjees) in Mina, where all Omani Hajjees convene for three days. The socio-demographic characteristics, the diabetes profile and the knowledge about complications of diabetes of all DOH were ascertained; their random blood sugar (RBS) was tested. Of 10,800 Omani who performed the Hajj in 1996, the 169 Hajjees with diabetes mellitus (prevalence rate 16 per 1000) included four per cent insulin dependent (IDDM), seven per cent on dietary control, and 89% on oral hypoglycaemic agents. Almost all DOH (98%) were medically examined before their departure for Hajj. All Hajjees with IDDM and 96% on oral hypoglycaemic agents brought their medicines with them. During the Hajj period, 2.4% of DOH had RBS < 75 mg/dl, 14% 75-110 mg/dl, and 49% were hyperglycaemic (RBS > 200 mg/dL). About half of the DOH (48%) knew the clinical presentation of hyperglycaemia, a fourth (24%) about symptoms of hypoglycaemia. Only 9.5% were trained to test themselves for blood sugar. The median age of DOH was 54 years (inter-quartile range 50-62). Some 7.5% females and 4.9% of males were obese (body mass index > 30). Forty seven (28%) of the DOH had other coronary heart diseases, hypertension or both. DOH moved between Holy places (four journeys; 5-15 km long) on foot (40%), by car or bus (31%), or both (29%). All DOH except one were not wearing protective shoes, 70% did not have identification wrist bands that show their diabetic status and regimen for treatment. Four per cent lost their way during Hajj, four per cent suffered from heat exhaustion, three per cent had cut wounds, 1.2% had pneumonia, and two per cent went into coma. There is a need for a special health education programme and for special services for the diabetics during Hajj. Hajjees should learn about symptoms and signs of hypoglycaemia, were protective shoes and identifying wrist bands. Specialised services for the diabetics would alleviate a lot of the stress during Hajj among the diabetics.