ObjectiveProstate cancer survivors have reported cognitive complaints following treatment, and these difficulties may be associated with survivors' ongoing cancer‐related distress. Intolerance of uncertainty may exacerbate this hypothesized relationship by predisposing individuals to approach uncertain situations such as cancer survivorship in an inflexible and negative manner.We investigated whether greater cognitive complaints and higher intolerance of uncertainty would interact in their relation to more cancer‐related distress symptoms. MethodsThis cross‐sectional, questionnaire‐based study included 67 prostate cancer survivors who were 3 to 5 years post treatment. Hierarchical multiple regression analyses tested the extent to which intolerance of uncertainty, cognitive complaints, and their interaction were associated with cancer‐related distress (measured with the Impact of Event Scale‐Revised; IES‐R) after adjusting for age, education, physical symptoms, and fear of cancer recurrence. ResultsIntolerance of uncertainty was positively associated with the IES‐R avoidance and hyperarousal subscales. More cognitive complaints were associated with higher scores on the IES‐R hyperarousal subscale. The interaction of intolerance of uncertainty and cognitive complaints was significantly associated with IES‐R intrusion, such that greater cognitive complaints were associated with greater intrusive thoughts in survivors high in intolerance of uncertainty but not those low in it. ConclusionsProstate cancer survivors who report cognitive difficulties or who find uncertainty uncomfortable and unacceptable may be at greater risk for cancer‐related distress, even 3 to 5 years after completing treatment. It may be beneficial to address both cognitive complaints and intolerance of uncertainty in psychosocial interventions. Copyright © 2014 John Wiley & Sons, Ltd.