This study was designed to examine the in vitro antiproliferative activity of the methanol crude extracts of six Salvia species: Salvia dominica L. leaves, Salvia lanigera Desf. aerial parts, Salvia menthaefolia Ten. roots, Salvia palaestina Benth. aerial parts, Salvia sclarea L. roots and Salvia spinosa L. aerial parts. Extracts were screened for their possible antitumoral activity by MTT test on nine human cancer cell lines: glioblastoma (DBTRG-05MG, T98G, U-87MG), colorectal adenocarcinoma (WiDr and HT-29), prostate adenocarcinoma (MDA Pca2b), choriocarcinoma (JEG-3), endometrium adenocarcinoma (HEC-1A) and B lymphoblast (CIR). IC(50) values were determined for only five extracts and ranged from 90 to 400 microg/mL approximately. Salvia menthaefolia extract exhibited marked antiproliferative activity against all tumor cell lines showing lower IC(50) values, while S. spinosa, S. sclarea and S. dominica extracts showed a degree cytotoxic activity dependent on the cell line type. Finally S. palaestina extract revealed a moderate antiproliferative effect only against three cell lines. Salvia lanigera extract displayed toxic activity at all concentrations tested. The results strengthen the evidence that the genus Salvia could be considered a natural resource of potential antitumor agents.