The rotary diversified diet, used in the management of environmental illness, consists of eliminating prohibited foods from the diet and rotating remaining non-prohibited foods and their "food families" within a regular cycle. We assessed the adequacy of nutrient intakes in 22 women prescribed the diet, described the nature of supplement use, and assessed the relationship between adherence and nutrient intake levels. Except for calcium and folacin intakes, mean nutrient intakes met or exceeded recommended levels. No subjects had calcium intakes above the adequate intake for calcium; 72.7% had folate intakes below the estimated average requirement. Intakes of other nutrients, except thiamin and magnesium, were below the estimated average requirement in less than 25% of the sample; 31.8% and 45.5% of subjects, respectively, had thiamin and magnesium intakes at this level. Those who adhered more closely to the rotary diversified diet had higher intakes of vitamin C, vitamin B6, folate, and fibre than did those who followed the diet less closely. Supplements conferred some nutritional benefits; however, supplemental niacin and magnesium intakes exceeded tolerable upper intake levels. Those prescribed the rotary diversified diet require nutrition counselling from dietitians to cope with the complexity and restrictiveness of the diet.