Background: Poor adherence to antihypertensive treatment has been a global challenge. It is necessary for health care providers to identify the factors affecting treatment adherence. Objectives: The present study aimed to investigate the adherence to treatment and its related factors in patients with hypertension. Methods: A cross sectional study carried out from September 2017 to March 2018 on 600 patients with hypertension who were covered by urban community health centers in Kerman, Iran. The Persian version of Morisky medication adherence scale (P-MMAS-8) and hypertensive treatment adherence scale (HTAS) were used for assessing adherence to the medication and treatment, respectively. Data was analyzed by SPSS software version 19.0 using Independent t-test, ANOVA and logistic regression. Results: The mean age of participants was 56.44 ± 12.3 years, with the majority of them (70.0%) being female. Poor adherence to medication and treatment was found in 304 (50.7%) and in 238 (39.7%) patients, respectively. Age, level of education, and the presence of concurrent medical disease and psychological disorder significantly predicted the adherence to treatment. Conclusions: Poor adherence was common among hypertensive patients in our primary health care setting. Therefore, it is necessary for our health care providers to identify the factors associated with poor adherence to be intervened timely.