Although food insecurity has been associated with a disadvantageous socioeconomic status, especially in older adults, its association with comorbidities is less clear. The scope of the present cross-sectional study was to assess the prevalence of food insecurity among older adults and evaluate the association between food insecurity, malnutrition, chronic disease, multimorbidity and healthcare utilization. A total of 121 older adults (mean (standard deviation) age: 72.6 (8.1)) were recruited from a Primary Care Health Center from 10 August 2019 to 10 September 2019. Food insecurity and malnutrition status were assessed by the Household Food Insecurity Access Scale and Mini Nutritional Assessment tool, respectively. Recorded variables included financial, family data and comorbidities. The prevalence of food insecurity in the sample reached 50.4%, with men and older adults malnourished or at risk for malnutrition, exhibiting high risk for food insecurity. Multimorbidity, frequency of health care utilization and medication adherence were not associated with food insecurity, possibly due to the free health services and remunerated medications offered by the Greek government. However, male gender and malnutrition risk were significant predictors of food insecurity in the multiple logistic analyses. This study highlights the need for mainstreaming food insecurity assessment among older adults with comorbidities, especially those at risk for malnutrition.