The blow flies (Diptera: Calliphoridae) include many species that are important as nuisance flies, disease transmitters, and pollinators and are also very important in forensic entomology. Understanding the presence, phenology, and abundance of species in a given area is important in analysing a forensic case and is also valuable in developing baseline databases for comparison over time. Little work on Calliphoridae has been conducted in Manitoba, Canada. Baited traps were deployed at eight sites around the Winnipeg area throughout the insect season in 1978, 1979, and 1980. Five species, Cynomya cadaverina (Robineau-Desvoidy), Protophormia terraenovae (Robineau-Desvoidy), Phormia regina (Meigen), Lucilia illustris (Meigen), and L. sericata (Meigen), were regularly collected, with Calliphora spp. Robineau-Desvoidy collected much less frequently. The same species were collected consistently over the years of trapping, although abundance varied greatly even at the same sites.