Lars Karlsson started his hockey career in 1976 with Kiruna AIF and played there until 1979. He played with Leksands IF from 1979-84 and in 1984-93 played with IF Björklöven, winning the Swedish title with them in 1987. Karlsson finished his career in 1993-94 with Lycksele SK. Karlsson was capped with the Swedish national team 73 times. He won an Olympic bronze in 1988 and was World Champion in 1987. He also won bronzes at the 1978 European Junior Championships and 1979 and 1980 World Juniors. He was awarded the Stora Grabbars Märke (Big Boys’ Badge) #143 in ice hockey.