Ciprofloxacin is a chemotherapeutic agent mainly used in the treatment of the pulmonary and urinary tract infections but is also known for its anticancer properties. The aim of these study was to check the anticancer effect of ciprofloxacin on selected five cell lines. Human non-small cell lung cancer line A549, human hepatocellular carcinoma line HepG2, human and mouse melanoma lines (A375.S2 and B16) and rat glioblastoma line C6 were used for evaluation of cytotoxic properties of ciprofloxacin (in concentration range: 10-1000 microg/mL). Viability was established using trypan blue assay and MTT. Ciprofloxacin induced morphological changes and decreased viability of A549 cells in a concentration and time dependent manner. In case of A375.S2 and B16 cell lines, cytotoxicyty of ciprofloxacin was observed but we were not able to eradicate all cells from A375.S2 and B16 cultures. HepG2 line was sensitive to ciprofloxacin, but this effect was independent from concentration and incubation time. The C6 cells were insensitive to ciprofloxacin. Our results showed that ciprofloxacin can be potentially used for the experimental adjunctive therapy of lung cancer.