Appropriate self-care practices, including nutrition and medication compliance, are essential to satisfactory control of diabetes mellitus (DM). This descriptive study assesses self-care practices, and their relationships to glycaemic control in adults with DM in Jamaica. A pre-tested structured interview and anthropometric measurements were carried out on 98 women and 35 men, randomly selected from a population (n = 510) of adult clinic patients. HbA1c was used as the index of glycaemic control. Selfcare practice scores indicated the extent of compliance with appropriate lifestyle practices. Data were analyzed using the Statistical Package for the Social Sciences (SPSS). Men (median age, 62 years) were significantly older (z = 2.64, p = 0.008) than the women (55 years). The median duration of DM was: men, seven years; women: 10.5 years. Sixty-nine per cent were being treated with insulin. Only 45% reported full compliance with medications. Their median body mass index (BMI) was 29.1, (16.6 – 47.4) kg/m2. Eighty-one per cent were overweight or obese. Forty-six per cent described diet and/or obesity as contributing to their diabetes. Eighty-five per cent had consulted a dietitian but only 56.4% reported being on a “special diet”. Only 16.5% reported not taking any sugar. Self-care scores were inversely related to HbA1c% (p = 0.008), BMI (p = 0.001), sugar intake (p = 0.005) and were lowest in the area of weight control and exercise. Only 23% had blood glucose controlled to HbA1c # 6.5%. In women, HbA1c% levels were inversely related to compliance with medication (p = 0.004). Glycaemic control in adults with diabetes mellitus is related to their self-care practices, especially weight control, exercise and medication compliance.