Zn-based (capped with thioglycolic acid (TGA) or 3-mercaptopropionic acid (MPA)) and Cd-based quantum dots (QDs) (capped with TGA or L-glutathione), were synthesised and used to investigate their cytotoxicity to human pancreatic carcinoma cells (PANC-1) in absence and presence of UV irradiation. Zn-based QDs exhibited less intrinsic cytotoxicity than the Cd-based QDs, however, the excitation of 50 µg/mL-QDs using UV lamp significantly enhanced the cytotoxicity of both QDs. After 15 min of UV irradiation, the viability for cells exposed to Cd-based QDs capped with TGA or glutathione was 49% ± 6% or 56% ± 3%, respectively. The corresponding cell viability in the control test was 83% ± 8% after 15 min of UV irradiation. In turn, the viability for cells exposed to Zn-based QDs capped with 3-MPA or TGA was 64% ± 3% and 52% ± 3%, respectively, after 30 min of UV irradiation; the cell viability in the control test was 80% ± 7% for the same UV irradiation time. Laser scanning confocal analyses evidenced that QDs can be easily ingested by PANC-1. Based on their good compositional stability, Zn-based QDs capped with 3-MPA can be considered a promising material for nanomedicine applications until concentrations of 200 µg/mL.