To assess the effectiveness of annual mass ivermectin treatment over 20 years in achieving elimination of onchocerciasis, we conducted a cross-sectional study between May 2021 and March 2022. A total of 540 individuals aged 5 years and above from rural farming communities selected were skin-snipped for dermal microfilariae (mf) by standard technique. Prospection of Simulium black flies was done at Lolo and Ibii Rivers. Structured questionnaires were used for the level of awareness, attitude and perceptions (KAP): onchocerciasis, vectors, treatment, drug compliance, benefits and socio-economy. Results revealed an overall mf prevalence of 12.8% and black fly infection rate (0.7%), infectivity and transmission potentials of (0.0%) indicative of non-transmission. These values contrasted with earlier reports in the range of 22%-68% for mf and 20.2%-48.2% infective rates suggesting the efficacy of mass ivermectin treatment in halting onchocerciasis. Participants had a high level of awareness about drug distribution. Benefits, dislikes and challenges of ivermectin were reported. We concluded that annual mass ivermectin treatment creditably reduced the microfilarial load and treatment in the study communities.