Context: Lansium domesticum corr. is a member of the family Meliaceae, and known locally as duku and has been used traditionally in the prevention and treatment of various illness. Aim: To study the cytotoxic effect and morphological changes of human colorectal adenocarcinoma cells (HT-29) treated with different duku (Lansium domesticum corr.) extracts. Methods: The L.domesticum corr. fruit extracts were processed involving three different solvents; methanol, ethanol and ethyl acetate. HT-29 cell lines were treated with different concentrations of L. domesticum corr. (0-100 μg/ml) extracts for a total of 24, 48 and 72 hours. Cytotoxicity of cells line was determined by using MTT assay as per IC50 values. Results: Methanol extract of L. domesticum corr. showed IC50 value at 6.79 ± 0.00 μg/ml and 50.0 ± 0.00 μg/ml respective, while ethyl acetate extract of L. domesticum corr. reached IC50 value at 86.00 ± 0.08 μg/ml, and 96.0 ± 0.12 μg/ml. There was no IC50 value of ethanol extract from L.domesticum corr. Only methanol extract showed toxicity towards HT-29 cells line. Conclusion: To the best of our knowledge, this is the first repeat the exploring the effect of duku (L. domesticum corr.) extract on HT-29 cells line.