The purpose of this study was to examine the dietary intake of both inpatients and outpatients with schizophrenia in the Portuguese population as a potential key contributing factor to the poor physical health profiles, and understand the relationship of diet quality to other lifestyle factors. Participants of this cross-sectional study completed a semi quantitative food frequency questionnaire. Diet quality was determined by adherence to the Mediterranean Diet. In addition participants completed the International Physical Activity Questionnaire-Short-Form and Pittsburgh Sleep Quality Index. Tobacco smoking was assessed through a series of general questions. A total of 100 patients (50% inpatients and 28% female) with schizophrenia were included in the final analysis. Patients reported a high consumption of caffeine, while deficits were evident for fibre and folate intakes, when compared to the European Food Safety Authority recommendations. Both inpatients and outpatients reported poor to moderate diet quality. Smokers reported poorer diet quality when compared to non-smokers (p < 0.001). Dietary intake, and its relationship to other lifestyle components, should be considered for intervention, in order to improve physical health of people living with schizophrenia.