Background and Objectives: Emerging evidence is placing the Mediterranean diet (MD) in the spotlight as a potential dietary model that could benefit inflammatory bowel disease (IBD) patients in terms of prevention and progress of the disease. The main aim of the present study is to shed some light on the relationship between the adherence to the MD and the degree of disease activity, as well as the quality of life in patients with Crohn's disease (CD). Materials and Methods: An administered questionnaire was used to assess and record a number of parameters, including recent medical and weight history, anthropometric characteristics, disease activity (in remission or active disease), and quality of life of both male and female CD patients. Moreover, the level of compliance of the participants to the Mediterranean diet model was evaluated and its relationship with disease activity and quality of life was investigated. Results: Adherence to the MD was significantly higher in patients with inactive disease than in those with active disease (p = 0.019). According to the correlation analysis conducted, adherence to the MD was negatively correlated with disease activity (p = 0.039) and positively correlated with quality of life (QoL) (p = 0.046) of the participants. Intake of fruits, vegetables, and dairy products was significantly higher in remission patients (p = 0.046, p = 0.001, p = 0.041, respectively). Conclusions: We conclude, according to the findings of the study, that adherence to the MD is associated with disease activity and QoL in patients with CD. Future research should focus on MD intervention studies on IBD patients in order to assess its effect on modulating disease activity/course and related inflammatory biomarkers.