Background-The matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) are strongly implicated in tumour invasion and metastasis. Aims-To investigate the presence of individual MMPs and TIMPs in gastric career. Methods-The presence of MMP-2, MMP-3, MMP-9, TIMP-1, and TIMP-2, was identified in a group of gastric cancers (n=74) by immunohistochemistry using monoclonal antibodies. These antibodies were effective on formalin fixed, paraffin wax embedded sections. Results-A large proportion (94%) of gastric cancers contained MMP-2; MMP-1 and MMP-9 were also detected in 73% and 70% of tumours respectively. MMP-3 was only present in 27% of tumours. MMP-1 and MMP-9 were found predominantly in intestinal type tumours. TIMP-1 and TIMP-2, were identified in 41% and 57% of tumours respectively. Immunoreactivity for individual MMPs or TIMPs was not identified in normal stomach. Conclusions-This study shows the presence of matrix metalloproteinases, particularly MMP-2, and TIMPs in stomach cancer. Antibodies which are effective in formalin fixed, paraffin wax embedded sections are useful for the identification of MMPs and TIMPs in diagnostic specimens.