A series of novel N-aryl-5-(benzo[d][1,3]dioxol-5-ylmethyl)-4-(tert-butyl)thiazol-2-amines (C1–C31) were synthesized and evaluated for their antitumor activities against HeLa, A549 and MCF-7 cell lines. Some tested compounds showed potent growth inhibition properties with IC50 values generally below 5 μM against the three human cancer cells lines. Compound C27 showed potent activities against HeLa and A549 cell lines with IC50 values of 2.07 ± 0.88 μM and 3.52 ± 0.49 μM, respectively. Compound C7 (IC50 = 2.06 ± 0.09 μM) was the most active compound against A549 cell line, while compound C16 (IC50 = 2.55 ± 0.34 μM) showed the best inhibitory activity against the MCF-7 cell line. The preliminary mechanism of the inhibitory effect was investigated via further experiments, such as morphological analysis by dual AO/EB staining and Hoechst 33342 staining, and cell apoptosis and cycle assessment by FACS analysis. The results illustrated that compound C27 could induce apoptosis and cause both S-phase and G2/M-phase arrests in HeLa cell line. Therefore, compound C27 could be developed as a potential antitumor agent.