Introduction: The use of intralesional injection of collagenase Clostridium histolyticum (CCH) has become a valid treatment option in the management of Peyronie's disease (PD). Multiple studies have shown the drug's safety and efficacy. However, sparse literature exists on the utility of the injection protocol's 14-day “observation period,” in which patients are instructed to abstain from all sexual activity. Aim: To summarize the contemporary literature and report on our series of patients treated with CCH in an effort to explore the effectiveness of the postinjection observation period. Methods: We retrospectively reviewed the clinical course of men treated with at least one CCH injection at our institution from April 2014 through February 2017. Main Outcome Measures: The main outcome measure for our cohort was complication rate (hematoma, fracture). Secondary outcomes included progression to corrective surgery. Results: Of the 102 patients treated, 5 (4.9%) developed a corporal fracture. Four of these occurred outside the 14-day observation period. One fracture was managed conservatively and the rest underwent surgical exploration and repair. Twelve penile hematomas were reported; one of these patients was surgically explored because of suspicious magnetic resonance imaging findings. Seven patients (6.9%) progressed to corrective surgery. Conclusion: Penile hematoma and corporal fracture are serious complications that must be discussed with patients before initiation of intralesional CCH treatment. Little evidence exists to direct physicians on the proper management of post-CCH penile fractures; many caregivers and patients elect to treat these injuries conservatively and avoid surgical exploration. Further studies are warranted to generate discussion and reassessment regarding the safety and effectiveness of this 14-day observation period. Beilan JA, Wallen JJ, Baumgarten AS, Morgan KN, Parker JL, Carrion RE. Intralesional Injection of Collagenase Clostridium histolyticum May Increase the Risk of Late-Onset Penile Fracture. Sex Med Rev 2018;6:272–278.