In this descriptive study, individual structured interviews were conducted on a random sample of 35 men and 98 women from a population (n = 510) of clinic patients. Open questions sought to determine the extent of knowledge, motivation and barriers to lifestyle changes for control of diabetes mellitus (DM) in Jamaican adults. These were coded into themes and described. Other data were analysed using SPSS. Men (61.8 ± 14.8 years) were older than women (54.9 ± 13.7 years) and demonstrated less knowledge (p = 0.006). The respondents (71%) indicated the need for more education. Barriers to lifestyle changes and glycaemic control included a low education level (64%), inadequate knowledge (80%), lack of perceived risk (80.4%) and lack of self-monitoring (93%). Only 23% were controlled to HbA1c # 6.5%. The patients’ reference to the physicians as a primary source of information indicated the need for a collaborative team approach, and the incorporation of diabetes education as an indispensable service at this clinic.