The cDNA clone, SlPMSR, which codes for a putative methionine sulfoxide reductase (PMSR), was isolated from the tomato plant (Solanum lycopersicum L.). The PMSR protein, which could reduce methionine sulfoxide back to methionine, shared a high degree of identity with those proteins isolated from Arabidopsis thaliana (76%), Gossypium barbadense (75%), and Lactuca sativa (70%). The SlPMSR gene exists as at least one copy in the tomato plant, and its transcription was expressed strongly in the leaves and red mature fruits. The SlPMSR gene could be induced constantly by abscisic acid (ABA). Relatively high levels of SlPMSR transcripts were detected 6 h after salicylic acid (SA) treatment, and the transcript levels decreased rapidly until 12 h. The expression of the SlPMSR gene increased at 3 h after $H_2O_2$ treatment, and maintained a constant expression until 24 h. The transcripts of SlPMSR were unchanged after exposure to cold and were induced by mannitol and NaCl, and were increased slightly after treatment. These results indicate that SlPMSR may perform an important function in protecting the plant against abiotic and oxidative stresses.