OBJECTIVES: The study assessed economic burden of pharmacotherapy in hypertension management on the National Health insurance Scheme (NHIS) of Nigeria, Health Maintenance Organizations (HMOs), the individual patients, and the companies as well as the economies of antihypertensives selection. METHODS: Two hundred and fifty case notes of hypertensive patients attending out-patient-department of the hospital (between August 1st – November 30th, 2011) were randomly selected. Selection criteria required that patients must be on at least an antihypertensive and first diagnosed after 2003. These were assessed for costs of pharmacotherapeutic management of hypertension as well as drug funding status.Requisite patients’ information extracted from case notes included: hospital number, age, gender, occupations, drugs, dosages and patients’ drug funding status. Drugs’ prices were obtained from the hospital billing guide. Data analysis was carried out using Microsoft excel and SPSS v16.0 for windows. RESULTS: Two hundred and eight of the selected case notes met the study criteria out of which 125 (60.1%) were males, while 83 (39.9%) were females. Most of the patients work for the government 98 (47.1%). Others either work for private companies 51 (24.5%) or are self-employed 25 (12%). Retirees constituted 11.5% of the lot while 4.8% were unemployed. Diuretics were the most economical at an average monthly cost per prescription of ₦858.6 ($5.51) and was closely followed by the beta-blockers at ₦1,101.1 ($7.07). The total estimated monthly cost of the antihypertensives prescribed in the study was ₦892,650 ($5730.93). HMOs having 104 (50.0%) of the cohort as enrollees incurred most of the cost at ₦446,325.0 ($2865.47). NHIS and Companies with 75 (36.0%) and 17 (8.2%) of the enrollees respectively incurred ₦321,354.0 ($2,063.14) and ₦73,197.3 ($469.94). Private patients 12 (5.8%) incurred the least at ₦51,773.7 ($332.39).   CONCLUSIONS: HMOs and NHIS incurred most of the cost of antihypertensives prescribed and diuretics were the most economical of all.