 The study found that non-adherence to medications is a common problem among Saudi patients with hypertension and diabetes mellitus. Factors such as gender, age, literacy level, duration of illness and type of chronic disease were negatively associated with medication adherence. Low and medium adherence rates were observed, which could contribute to the failure of achieving therapeutic outcomes. Further research is needed to evaluate the applicability of the MoriSky Medication Adherence Scale, MMAS-8, as a tool of measuring medication adherence among Saudi patients with chronic diseases. Additionally, strategies to improve patient adherence should be explored and tested in different patient groups. This article was authored by Mohamed Rashid, Ahmed Khalidem and Muteb Duayfingal Harbi.