The sequencing of 304 nt of the mitochondrial COI gene was successfully performed on single legs of adult specimens and also on a complete maggot and pupa. This proves that the technique used is applicable in forensic case work studies. The 304 nt fragment of the COI gene can be considered a valuable Chrysomyinae species identification tool for forensic entomology in Belgium-France. The maximum intraspecific variability for all three Belgian-French Chrysomyinae species with forensic interest is 1.3 percent, and the minimum site-specific variability is 6.6 percent. This clear difference between the threshold levels enables forensic entomologists to distinguish between forensically important Chrysomyinae species in Belgium and France by DNA barcoding. The sixty-eight Chrysomyinae specimens sequenced in this study were collected from 15 locations in Belgium and France since 2003. They were at different developmental stages (adults, larvae, and pupae). All the specimens were collected on mammalian cadavers by hand net or yellow trap for adults and with spoons for larvae and pupae. In addition to describing the specimens, this report describes the DNA extraction, PCR amplification and DNA sequencing, DNA sequence alignment, and phylogenetic analysis. 4 tables, 1 figure, and 31 references