New 1,8-naphthalimido derivatives with 2,3 and 4 carbon chains bearing a number of different functionalities were synthesized and tested against a panel of breast cancer MCF-7, colon cancer HCT-15 and pancreatic cancer BxPC-3 cell lines. Generally structures with shorter alkyl chains were more active, with the one exception of the amide containing a p-nitrophenyl group. GI50 values (μM) were determined for the most active compounds. Three compounds exhibited GI50 values below 5 μM, two with MCF-7 cells, and one other with HCT-15. Compounds with different functionalities demonstrated cell line specificity: the MCF-7 cell line was more sensitive to an urea derivative (6f), the growth of HCT- 15 cells were most affected by a triazole (9d), while the BxPC-3 cell line was inhibited in a higher extend by a guanidine (4a).