Background/objective The interplay between individual's mood fluctuations and nutrition has important health implications. However, little information is available on the relationship between dietary intake and mood state in a population with metabolic syndrome (MetS). The aim of the present study was to evaluate the association between dietary intake and mood state in subjects with MetS. Methods This cross-sectional study was based on the baseline data of 84 volunteers (mean age 49 ± 1 years) recruited into the Metabolic Syndrome Reduction in Navarra-Spain (RESMENA-S) study. Mood state was determined using a mood thermometer visual analogue scale. The dietary intake was assessed with a 48-hours weighted food record, from which a Healthy Eating Index (HEI) score was obtained. Anthropometrical measurements and biochemical parameters were also analysed. Results At baseline, a positive association between mood thermometer and HEI was observed. Among the 10 HEI components, vegetables, fruits, calories from lipids, saturated fatty acids, and dietary variety were related with higher mood. Moreover, those participants who consumed more water, fibre, vitamin B6, ascorbic acid, tryptophan, magnesium, and selenium have higher mood. Discussion In conclusion, an association between both the overall dietary pattern and isolated nutrients with mood state was observed. The analyses of both dietary patterns and specific nutrients are important to determine the association between mental disorders and dietary intake.