Summary in EnglishBackground: The relationship between meat consumption and cancer risk has been investigated in many studies, but the results have been inconclusive for several cancer sites. This master thesis represents a meta-analysis of meat consumption and risk of all types of cancers which had been investigated in a sufficient number of studies to be included. Methods: The analysis was conducted by first searching several databases for studies on meat consumption and cancer risk, from their inception to September, 2007. Relative risks, incidence rate ratios and odds ratios were pooled by use of a random-effects model. Results: For all studies combined there was an increased risk of cancer of the lung, pancreas, liver, colorectum, breast, ovaries, endometrium, prostate and kidney with a high total meat intake. Higher intake of red meat was associated with increased risk of cancer of the mouth and pharynx, esophagus, lung, stomach, pancreas, colorectum, breast, endometrium, kidney and of non-Hodgkin’s lymphoma, while higher intake of processed meat was associated with cancer of the mouth and pharynx, nasopharynx, larynx, esophagus, stomach, pancreas, colorectum, breast, prostate and adult and childhood brain cancer (maternal intake during pregnancy). In addition, several individual meat items were associated with increased risk of some types of cancer. For some sites and meat types there are some discrepancies between the results from case-control and cohort studies. Conclusion: More studies are needed, particularly large population-based case-control and cohort studies to confirm some of these findings and for those sites investigated by too few studies to date. However, for some of the most investigated sites, including breast, lung, esophagus, pancreas and stomach, it seems likely that reducing meat consumption will be an important goal in decreasing cancer risk. For colorectal cancer it seems very likely that reducing meat consumption will decrease the risk.