Introduction: The risk of cancer in patients with solitary colorectal juvenile polyps (JPs) is poorly investigated and several studies have reported polyps with dysplastic and adenomatous alterations. We aimed to investigate the long-term risk of cancer and mortality in these patients by merging data from national registers and comparing them to a matched control cohort. Materials and Methods: Patients with a solitary JP were identified in The Danish National Pathology Register and Data Bank (DNPR). The included patients were matched on sex, age, and place of birth with 50 controls. The groups were then analyzed for risk of cancer using the Danish Cancer Registry and mortality using the Danish Cause of Death Registry. Results: We identified 1781 patients with solitary JPs and matched them with 83,713 controls. The mean follow-up time was 7.65 years for cases and 7.36 years for controls. The risk of cancer, including colorectal cancer, did not differ for the two groups and when adjusting for sex and year of birth, the hazard ratio (HR) was 1.15 (confidence interval [CI] 95% 0.94–1.41, p = 0.162). There was no increased risk of death (HR: 1.07, CI 95% 0.88–1.30, p = 0.486). The risk did not differ for different age groups or sex. Conclusion: There is no increased risk of cancer or mortality for patients with solitary colorectal JPs. Thus, endoscopic follow-up may be safely omitted in these patients.