Objective. To compare dietary patterns and food and macronutrient intakes among adults in three ethnic groups in rural Kenya. Design. In the present cross-sectional study, dietary intake was estimated in adult volunteers using two non-consecutive interactive 24 h recalls. Dietary patterns were assessed from the number of meals and snacks per day and from the food items and major food groups registered, and their contribution to energy intake (EI) was calculated. Anthropometric values were measured and sociodemographic data obtained using a questionnaire. Setting. A cross-sectional study was conducted in the Bondo, Kitui and Transmara districts of rural Kenya. A high prevalence of food insecurity in Kenya underlines the importance of describing the dietary patterns and intakes in different Kenyan ethnic groups. Subjects. A total of 1163 (61% women) adult Luo, Kamba and Maasai, with a mean age of 38.6 (range: 18–68) years, volunteered to participate. Results. Dietary patterns and food groups contributing to EI differed significantly among the ethnic groups. Mean EI ranged from 5.8 to 8.6 MJ/d among women and from 7.2 to 10.5 MJ/d among men, with carbohydrates contributing between 55.7% and 74.2% and fat contributing between 14.5% and 30.2% of total EI. Mean protein intake ranged from 0.72 to 1.3 g/kg per d, and EI:BMR ratio ranged between 1.1 and 1.6 in both sexes, and was highest among the Luo. Prevalence of underweight (BMI <18.5 kg/m2) was 13.7%, 20.5% and 24.2% in the Luo, Kamba and Maasai, respectively. Conclusions. The degree of food insecurity measured as a degree of undernutrition and as dietary patterns differed considerably among the ethnic groups. The Maasai and Kamba in particular were exposed to food insecurity. Copyright © The Authors 2011.