Stable fly collections were conducted to study the species composition and daytime activity of Stomoxys spp. (Diptera: Muscidae) in Peninsular Thailand (Songkhla, Trang, Pattalung, Nakon SiThammarat, and Satun provinces). Vavoua traps were used for fly collections in wet and dry seasons each year. Four Stomoxys species were found, S. calcitrans (L.) (Diptera: Muscidae) being the most common with 2,512 specimens (87.43% of captures), followed by S. indicus (Picard) (Diptera: Muscidae) with 306 specimens (10.65%), S. sitiens (Rondani) (Diptera: Muscidae) with 44 specimens (1.53%), and S. uruma (Shinonaga and Kano) (Diptera: Muscidae) with 11 specimens (0.39%). Subsequently, Songkhla Province was further selected to be a potential collection site to conduct a 1-yr abundance study, due to mixed crop-livestock farming in one place. Stomoxys calcitrans was predominant from 0800 to 1000 h with 4,921 specimens (93.6%) while S. indicus with 317 specimens (6%) and S. sitiens with 19 specimens (0.4%) were numerically dominant from 0600 to 0800 and 1600 to 1800 h. A proportion of male and female of each species was also established. This overall finding could be used as an ideal for nationwide species distribution status for the guidance of appropriate fly control. This information can lighten the way for the future control measures program activity of stable flies in Thailand.