Despite the availability of effective antihypertensive medications, blood pressure (BP) control is suboptimal. High medication regimen complexity index (MRCI) is known to reduce adherence and may be the reason for poor BP control. However, there is no data in the present study areas. Hence, the aim of this study was to assess MRCI and its association with adherence and BP control among hypertensive patients at selected hospitals of South Gondar Zone. A hospital based cross sectional study was conducted from December 1, 2020 to February 30, 2021 at selected hospitals of South Gondar Zone. Medication regimen complexity and adherence was evaluated using 65-item validated tool called MRCI (Text removed at time of retraction. See retraction notice for more information.). Multivariable logistic regression analysis was done to determine the association between predictive and outcome variables. About 3.3% of participants were classified as having high HTN specific MRCI whereas 34.75% of participants were classified as having high patient level MRCI. (Text removed at time of retraction. See retraction notice for more information.) Being illiterate, and having low HTN MRCI were more likely to have controlled BP in adjusted analyses. On the contrary, (Text removed at time of retraction. See retraction notice for more information.) not having health insurance, and having lower monthly income were less likely to have controlled BP. A considerable proportion of patients had high MRCI. Having low HTN MRCI was more likely to have controlled BP. Simplification of a complex medication regimen for patients with HTN should be sought by physicians and pharmacists to improve BP control.