Use of moist snuff is widespread in Sweden. In 2004 approximately 8oo,ooo Swedes were daily users which corresponds to 22% of the male population and 3% of the female population. The aim of the present study was to evaluate the effect of Swedish moist snuff extract on PDLfibroblast growth and hard tissue production and compare with moist snuff extract from USA. Periodontal ligament cells (PDL-cells) were obtained from 3 healthy subjects (1 female 14 years, 2 males 14 and 17 years) from the root surface of premolars extracted for orthodontic reasons. The cells were isolated from explants and grown in Dulbecco's Modified Eagle's Medium (DMEM) supplemented with 10% fetal calf serum (FBS) and cultivated in 37 degrees C with 5% CO2 in air. Snuff extract in concentrations 0.3%, 1% and 3% (in DMEM with 1% FBS) was tested. Cells from each individual were tested three times, each time in triplicate. Photographs were taken at o and 24 hours with a digital camera and analysed in terms of growth and morphology. Then the cell suspension was frozen and later thawed for examination of the production of alkaline phosphatase after exposure to different snuff concentrations. This in vitro study has shown that PDL cells from 3 different subjects demonstrated a reduced number of cells at exposure to 3% of both Swedish and American snuff extract.The production of alkaline phosphatase after 2 hours was similarly reduced from cells exposed to 3% snuff extract. Further studies have to be made to understand the effect of smokeless tobacco on periodontal tissues. However, from this study can be concluded that smokeless tobacco has biological effects in terms of reduced PDL cell growth and production of alkaline phosphatase