The antitumour activity of the ethanolic extract of leaves of Holoptelea integrifolia (EHI) has been evaluated against Dalton′s ascitic lymphoma (DAL) in Swiss albino mice at the dose of 250 and 500 mg/kg, body weight. The experimental parameters were evaluated like tumour volume, tumour cell count, viable tumour cell count, mean survival time and increase in life span to assess antitumour activity. The extract was administered orally for 14 consecutive days to tumour bearing group of animals. The extract increased the life span of DAL treated mice and restored the hematological parameters as compared with the DAL bearing mice in a dose-dependant manner. The study revealed that the EHI showed significant antitumour activity in tested animal models.