Triatoma gerstaeckeri (Stal) is considered the main vector for the transmission of Trypanosoma cruzi to human populations in the north and northeastern areas of Mexico. Since this species have been frequently collected infected by T. cruzi, close to human dwellings, it was necessary to estimate its vectorial capacity. Two hundred eggs recently laid were collected; after hatching, the emerged 146 first-instar nymphs were placed in some plastic containers and fed once a week on restrained rabbits. They were observed along feeding and half an hour after. Most triatomines fed and defecated in more than ten min (except on first and second instars). Mean developmental times were longer than nine months. This species could be consider a capable vector for the transmission of T. cruzi, which increase its vectorial importance.