In Myanmar, almost all of research activities are centered on Extension Division that organized with versatile agricultural specialists who are most likely to distribute research activities and new innovation technologies to remote areas. Pearl Thwe hybrid rice seed production was introduced in 2011/2012 in monsoon, for poverty alleviation and better living standard of farmers due to its higher yield. Sown area however is very limited to adopt. The purposes of this study are to evaluate the impact assessment of extension program by benefitcost ratio (B:C), and to examine the most effective methodologies by marginal effect. The seasonal data (580 sample sizes) were collected in 58 Townships of four State and Regions, from 2011/2012 to 2015/2016. The results showed that annual average growth rate of Pearl Thwe adoption in Nay Pyi Taw, Kachin, Kayin, Chin, Tanintharyi, Bago and Magway Region/State are satisfied while the rest State and Region are highly unsatisfactory. Nevertheless, Sagaing, Mandalay, Mon, Shan and Ayeyarwaddy Region/State increased adoption areas yearly even having decreasing growth rate. Among still operating various extension methods in Myanmar, field day, media and field-trial are the best, and demonstration and farmer-field-school are also satisfied whilst integrated method, workshop, other method (traditionally), training and group discussion methods are unsatisfactory for hybrid rice adoption, in accordance with cost (applied extension methodologies) and benefit (Pearl Thwe’ adoption). By the perception and perception score of Township Officer, farmer field school, workshop, other method, integrated method, the media were unacknowledged, and market access and input are constraint factors while technical assistance and source of seed are most likely convenient factors. In order to promote the reliable extension methodologies in Myanmar, the policy makers should try to be more familiar to the media and farmer-field-school to farmers as field day, on farm-trial and demonstration.