Overloading of the emergency departments in hospitals is, in Sweden, a common problem that is often blamed on lack of access to primary care. We have conducted a cross-sectional study comprising more than 40% of the 347 837 inhabitants of Region Jönköping with access to complete individual data on healthcare consumption, personal doctor continuity, socio-economics, and accessibility data for all of the region's health centres. Individuals with high personal continuity at their own health centre had significantly fewer emergency room visits compared to those with the lowest continuity: for younger adults 55% and for elderly 34% fewer emergency room visits. Access to doctor consultations or to counselling nurses in primary care was not associated with a lower number of emergency room visits. Our results show the importance of personal doctor continuity also for the group of younger adults.