Rotheca serrata (Lamiaceae), a highly medicinal plant is used as an antidote for snakebite and the plant possesses medicinal properties like hepatoprotective, antitussive, antioxidant, anticancer, neuro-protective, used in rheumatoid arthritis and is also a α-glucoside inhibitor. This work aimed to study the anticancerous effect of Rotheca serrata (root and leaf) on cancer cell lines MCF-7 (breast cancer cell line) and Neuroblastoma SH-SY5Y. The results indicated that the Methanolic extract of Rotheca serrata (root and leaf) showed high anticancer activity. Different concentrations of plant extracts (25, 50, 100, 200, 400 μg/ml) were used to study the anticancerous activity, amongst which the significant results were obtained for 400 μg/ml concentration (both root & leaf). Effective anticancer activity against MCF-7 breast cancer cells was shown in methanolic extracts and were expressed as IC 50 values, in root (IC 50 value= 61.8259 ± 7.428 μg/ml) and in leaf (IC 50 value equals to 78.1497 ± 6.316 μg/ml). The MTT assay in case of neuroblastoma (SH-SY5Y) cell lines revealed that 400 μg/ml concentration of leaf methanolic extract showed effective inhibition of cancer cells with IC 50 value 37.8462 ± 2.957 μg/ml as compared to IC 50 value of root methanolic extract which was 57.0895 ± 2.351 μg/ml.