Purpose: This study was conducted to evaluate the association between intakes of potassium, magnesium, and calcium and diet quality in ischemic stroke patients. Methods: This study analyzed data from 285 subjects recruited from February 2011 to August 2014 in Seoul, Korea. Nutrition intakes were obtained from a semi-quantitative food frequency questionnaire composed of 111 food items. The subjects were divided into 4 groups by quartiles according to intakes of potassium, magnesium, and calcium. Index of Nutritional Quality (INQ), Mean Adequacy Ratio (MAR), and DQI-International (DQI-I) were analyzed for assessment of diet quality. Results: We found a positive association of intakes of these three minerals with MAR and DQI-I after adjustment for age, sex, education level, smoking, atrial fibrillation, and total energy intake. However, total moderation of DQI-I score in the Q4 group was significantly lower than that of the Q1 group. The age, sex, education level, and smoking, atrial fibrillation, and total energy intake-adjusted odds ratios of extensive cerebral atherosclerosis were inversely associated with intake of magnesium (Ptrend = 0.0204). However, this association did not exist with intakes of potassium and calcium. Conclusion: Potassium, magnesium, and calcium rich and high quality diet could be associated with decreased risk of ischemic stroke, in part, via effect on extensive cerebral atherosclerosis.