European lobsters (Homarus gammarus) have been overfished for decades as it is a highly valued species. Commercial catch per unit of effort (CPUE) in Skagerrak, Norway has decreased to historically low levels in the most recent decades, from over 500 tons year-1 in before the 1970s to below 60 tons year-1 in 2006. It has also been estimated that the landings caught by recreational fisheries make up over 60% of the total landings of lobsters in the Norwegian Skagerrak region. Recreational catches are not registered and it is therefore difficult to implement effective regulations. The regulations in place are restrictions in number of traps household-1, a minimum landing size (250 mm total length, measured from rostrum to telson) and fishing seasons (1st of October to 30th of November) and it is illegal to land and trade egg bearing females. As a tool to obtain knowledge and possibly guide use of marine protected areas (MPAs) as a potential conservational tool for European lobster, MPAs were established along the Norwegian Skagerrak coast in September 2006. Marine protected areas are geographical sites were fishing is illegal or very restricted. These MPAs were situated from the basis of the Oslofjord to the south of Norway. In these MPAs only fishing by hook and line is allowed. To analyze the effects and efficiency of these MPAs, data were obtained by controlled fishing inside the MPAs and in associated control areas (where fishing was allowed). The data runs from 2007 to 2015 and includes information about size, sex and where and when each lobster was caught. To analyze the data both generalized linear mixed models and linear mixed models were used. According to the results, MPAs were successful at protecting lobster. The CPUE was significantly larger in the MPAs compared to the control areas, indicating a larger population density. The mean body size increased rapidly from ~240 mm total length to ~300 mm from the start to the end of the study period in the MPAs, but remained around minimum landing length in the control areas. The sex-ratio of the lobster varied, but showed no clear trend and remained close to 1:1 during the study period. Further effects of the MPAs could include an increase in reproductive output from the MPAs, which could have positive effects both locally and regionally.