Intolerance of uncertainty (IU) has been found to be involved in several anxiety disorders, including generalized anxiety disorder and obsessive-compulsive disorder (OCD). Few studies have examined the role of IU in health anxiety (HA)/hypochondriacal concerns (HC). We conducted two studies exploring the associations between IU and HA/HC. The first study included undergraduates (n = 114) and indicated an association between IU and several HA/HC indices. When controlling for neuroticism, worry about illness was the single index of HA/HC that remained associated with IU. In the second study among bereaved adults (n = 126), IU was associated with one index of HA/HC but not when neuroticism and anxiety sensitivity were controlled. In both studies, IU was found to be more strongly associated with OCD symptoms and worry than with HA/HC.