Background <p>Cardiometabolic diseases are the leading cause of death worldwide and particularly in Lebanon, considering the increasing prevalence of risk factors among the population. In addition to disease and risk factor awareness, treatment adherence remains essential for improving patient outcomes.</p> Objective <p>This study aimed to assess the level of treatment adherence among Lebanese cardiometabolic patients, in light of the impact of the Lebanese economic crisis and associated drug shortages.</p> Methodology <p>A cross-sectional questionnaire-based study was conducted across Lebanon, from June 1 till November 30, 2022, among Lebanese cardiometabolic patients ≥ 18 years old, undergoing treatment for ≥ 6 months. Patients with concomitant mental disorders were excluded. Participants were recruited through convenience sampling from public areas, community pharmacies and outpatient clinics (<i>N</i> = 346). The dependent variables were assessed using the Lebanese Medication Adherence Scale (LMAS-14) and the Harmful Impact of Medication Shortages (HIMS) scale. Bivariate and multivariable analyses were conducted to investigate the potential associations.</p> Results <p>The level of adherence, as evaluated by LMAS-14, was positively associated with regular physical activity (B = 1.216) and retirement (B = 1.045) and negatively associated with being employed (B = -1.126). Patients residing in Baalbek-Hermel had the lowest levels as compared to those in Beirut (B = -2.233). The impact of the Lebanese drug shortage on adherence levels, as measured by the HIMS scale, was higher among occasional smokers than non-smokers (B = 1.568) and among employed patients than those retired (B = 1.804).</p> Conclusion <p>Despite the Lebanese economic crisis, the overall level of adherence of Lebanese patients with cardiometabolic diseases was shown to be adequate and the reported impact of drug shortages was minimal.</p>