BackgroundNon-adherence to medication is a common problem in managing chronic diseases, which are a significant public health concern globally. This study aimed to identify factors related to medication adherence among patients with chronic diseases in Saudi Arabia.MethodsA cross-sectional survey design was used to collect data through an online survey administered to 400 patients with chronic diseases residing in Jeddah between January and March 2023. The survey included questions about socio-demographic characteristics, chronic disease diagnosis, medication adherence, and factors that may influence medication adherence.ResultsThis study recruited 400 participants and found that the majority were female, with a mean age of 46.2 years, and most had at least one chronic disease, with hypertension and diabetes being the most common. The medication adherence score for the entire sample was 5.4, indicating moderate adherence. Overall, 22.9% of study participants had poor adherence to medications. Factors associated with medication adherence included age, gender, and education level, with older age, female gender, and higher education being positively associated with adherence. Medication-related factors such as the number of medications prescribed, medication complexity, and medication cost were also found to be significantly associated with medication adherence.ConclusionOur study of medication adherence among chronic disease patients in Saudi Arabia found that adherence rates were moderate, with several factors significantly associated with better adherence. Specifically, older age, female gender, and higher education level were positively associated with better adherence, while a higher number of prescribed medications, more complex medication regimens, and higher medication costs were all significant predictors of poorer adherence.