With retrospective cohort analysis to adjust for ascertainment, cumulative tumour risks for <i>SDHB</i> mutation carriers at ages 60 years and 80 years were 23.9% (95% CI 20.9% to 27.4%) and 30.6% (95% CI 26.8% to 34.7%).<h4>Conclusions</h4>Overall risks of clinically apparent tumours for <i>SDHB</i> mutation carriers are substantially lower than initially estimated and will improve counselling of affected families. Here, SDHB is linked to neoplasm.