Opuntia ficus-indica (L.) Miller is found at different locations around the world, and it is frequently infested by the false carmine cochineal, Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae). Hyperaspis trifurcata Schaeffer is a natural enemy associated to this pest, which has been reported at different environmental conditions around Mexico and South of United States of America. Even so, it is necessary to know more about the predatory response of this species on D. opuntiae for predicting its potential as biological control agent. The objective of this study was to determine the functional response of H. trifurcata females preying upon the first instar of D. opuntiae nymphs. Eight treatments (prey densities) were established (8, 16, 32, 64, 128, 256, 314 and 512 nymphs I) with 30 repetitions each. They were placed on an experimental arena using Petri dishes (Ø= 3 cm and 1.5 cm high) at 25 ± 2°C, 60 ± 5% H.R., and 12:12 L: O. The functional response curve was obtained by nonlinear least squares regression and by Roger´s equation. Hyperaspis trifurcata functional response was type II, with attack coefficient observed as typical from the Coccinellidae family (a’= 0.071 ± 0.0019), a short handling time and it has a theoretical maximum prey capacity (T/Th) of 433.2 nymphs/per day.