Litter size, an important reproductive parameter used in the management and conservation of brown bears (Ursus arctos), is determined from reported observations by the public in some areas. We compared brown bear litter sizes based on reported public observations with those obtained by counting young from a helicopter or the ground by researchers. Mean litter sizes based on public observations were lower and showed more variance between seasons (spring and autumn) than mean litter sizes based on research methods. Public mean litter sizes showed significant variation among years, unless data from at least 6 years were analyzed. In south-central Sweden annual correction factors ranging from 1.120–1.260 must be used to correct the mean litter size based on public observations to agree with the mean litter size obtained by research, depending on how evenly public observations are spread throughout the year.