BACKGROUND: Post-caesarean section pain is a problem in our environment. Though, many modalities for pain management exist, there is the need to investigate safer and affordable regimens that will provide adequate analgesia with minimal side effects and with ease of administration. Alternating doses of intramuscular acetaminophen and intramuscular pentazocine has been proposed to provide multimodal post-caesarean section analgesia. Though, its effectiveness in our environment has not been adequately investigated. A study of this nature comparing this regimen with the more commonly used intramuscular pentazocine became necessary to test if it provided comparable analgesia with similar side effects profile in the first 48 hours. METHODS: This was a prospective, comparative, randomized study that compared the two regimens with regards their analgesic and side effects profile especially the return of bowel sounds and the need for rescue analgesia for breakthrough pains. This was done during the period May, 2014 to May, 2015. Information about the study was provided to patients in the antenatal clinics, delivery suites and maternity ward slated to have caesarean deliveries. Allocation of eligible, consenting women with the aid of a computer software WINPEPI by Abrahamson to receive either intramuscular pentazocine alone or in alternate doses with acetaminophen. The total sample size was 142. Spinal anaesthesia was administered using 2.5mls of heavy bupivacaine pre-operatively before caesarean section was done as elective. Data was collected on socio-demographic characteristics, indication for surgery, intra-operative findings/events like duration of surgery. The pain scores and pain relief scores, duration for return of bowel sounds and side effects were also noted.