Abstract Catalase (CAT) is a common antioxidant enzyme in almost all living organisms. Currently, detailed reports on cucumber (Cucumis sativus L.) CAT (CsCAT) genes and tissue expression profiling are limited. In the present study, four candidate CsCAT genes were identified in cucumber. Phylogenetic analysis indicated that CsCAT1-CsCAT3 are closely related to Arabidopsis AtCAT1-AtCAT3, but no obvious counterpart was observed for CsCAT4. Intron/exon structure analysis revealed that only one of the 15 positions was completely conserved. Motif analysis showed that, unlike the CAT genes of other species, none of CsCAT genes contained all 10 motifs. Expression data showed that transcripts of all of the CsCAT genes, except CsCAT4, were detected in five tissues. Moreover, their transcription levels displayed differences under different stress treatments.