The aim of the following study was to examine the effects of the Ultraviolet (UV) Index and a personal ultraviolet radiation (UVR) intensity indicator on tanning behaviour compared with general, written information about sun protection. A population-based random sample in Sweden was randomly assigned to four groups receiving different information packages (n=3200). Questionnaires were sent before and after the summer of 2001. Positive attitudes towards sunbathing as well as tanning and sunburn frequencies decreased. Knowledge about UV radiation and the use of sun protection increased for all groups. There were no between-group differences. Sun-related behaviours and beliefs changed, but information about the UV Index or a personal UVR intensity indicator did not decrease sunbathing and sunburn more than general, written information.