Copaiba oleoresin is extracted from the trunk of <em>Copaifera </em>sp genus trees and used for treating wounds in several regions of Brazil. Its antimicrobial and anti-inflammatory effects have been proved, however there are no reports of activity on cell growth. Proliferation of MDBK (<em>Madin Darby Bovine Kidney</em>) cells was evaluated under the influence of different concentrations of Copaiba oleoresin. Control groups consisted of cells in medium without addition of oleoresin (M group) and cells in the medium with application of the solvent Tween 80 at dilution 10-3 (TM group). Decimal dilutions of 10-1 to 10-3 were shown to be toxic and, therefore, the proliferation studies were conducted from dilution 10-4 to 10-7. Cell growth was faster in all groups that received the Copaiba oleoresin dilutions in the first 24 hours, specially the 10-5 dilution group, which proliferation rate was 5,47 higher than that of M group. It was concluded that Copaiba oleoresin stimulates cell multiplication, which may be one mechanism of its positive effect on wound healing, in association with those previously known.