Twenty gastric carcinoma cases were studied for the detection of CD44 aberrant transcripts using a cDNA/PCR/blot-hybridization technique which can detect splice variants containing an aberrant exon 11 of the CD44 gene. All the tumor tissues as well as their metastatic foci demonstrated overexpression of CD44 splice variants of more than 1.0 kbp than corresponding normal gastric mucosas. Six out of nine (66.7%) well-differentiated or intestinal type gastric cancers overexpressed more than three aberrant transcripts, whereas ten out of eleven (90.9%) poorly differentiated or diffuse type cancers overexpressed single or two lower molecular weight variants. These results indicate that the detection of CD44 transcription variants can serve as a powerful tool for the diagnosis of gastric cancer. It is also suggested from the difference in variant expression pattern that well-differentiated type and poorly differentiated type gastric carcinomas have different genetic pathways.