A population of over 15,000 snuff users and tobacco chewers were observed for cytological, histological, and clinical evaluation. The original observation was for 5½ years. The same group was observed for an additional 4½ years, bringing the total time to ten years. Of the original group of 1,751 patients showing mucosal change, I was able to follow up 1,550. No patient developed carcinoma or serious mucosal changes. From this ten-year study we concluded that snuff, per se, or chewing tobacco do not act as carcinogens.