An ethanolic herbal extract residue was prepared from the seeds of premature fruits of Terminalia arjunaLinn. Different concentrations of it were tested against 1×106 million Dalton’s Lymphoma Ascites (DLA) tumourcells. At a 200 μg/ml concentration it registered 90% toxicity. Then its effect on the lifespan of mice with DLAtumour cells was studied. At high and low dosages of 50 and 10 mg. b. wt. kg-1 of herbal extract residue, it exhibited87.5% and 60.4% increase in the lifespan, respectively. Blood parameters such as percentage Hb, RBC andWBC counts were conducted with tail vein blood samples. Hb and RBC counts of treated mice were higher thanthat of tumour bearing mice, while WBC counts were lower. This is a good index of tumour recovery. Furtherstudies were carried out on mice with solid tumours to record volumes, along with a lifespan study. Low dosageof the herbal extract residue was able to control the tumour volume 35.1% and 32.9% increase in the lifespanwas noted both at high and low dosages, respectively.