INTRODUCTION: The optimal diagnostic approach for C. difficile infection (CDI) is controversial. Infectious Disease Society of America currently recommends a high sensitivity test such as a nucleic acid amplification test (NAAT) PCR, followed by a stool toxin enzyme immunoassay to confirm clinical suspicion of CDI. C. difficile PCR cycle threshold (Ct) is the number of cycles required for a signal to exceed background fluorescence with low numbers reflecting a larger C. difficile nucleic acid burden. Recent reports correlate Ct in symptomatic patients with disease severity and mortality. Data regarding the predictive value of PCR Ct in recurrence of CDI is preliminary. We aim to determine the association between Ct and recurrence of CDI. METHODS: This was an IRB approved, single-center retrospective chart review cohort of 76 randomly chosen patients ≥18 y.o., with completely unformed stools that were C.difficile NAAT positive. 10 patients were excluded due to lack of Ct values. Recurrence defined as any positive test for C. difficile within 3 months after treatment for CDI. Severe CDI defined as WBC >15,000 or creatinine ≥1.5 md/dL and fulminant disease as refractory hypotension, ileus or megacolon. Poor clinical outcome defined as severe or fulminant CDI, or death within 30 days of diagnosis. A t-test or Mann Whitney U test was performed on populations with or without a normal distribution, respectively. A scatterplot was generated with Ct values for patients with initial vs recurrent episodes of CDI. RESULTS: Of 66 patients, mean Ct values of 8 patients with recurrent CDI (12.1%) and 58 without recurrence were 25.71 and 26.15 respectively (P = 0.79). Recurrence rates after the initial episode of CDI (n = 4), 1st recurrence (n = 1), and 2nd/subsequent recurrence (n = 3) were 9.1%, 12.5% and 21.2%, respectively. Mean Ct values trended lower for patients with poor outcomes (25.40 vs 26.42, P = 0.37). CONCLUSION: In our single center study, Ct values did not associate with a recurrence of CDI. Our findings suggest that Ct cannot be used to predict which patients will be at risk for recurrent CDI. The trend of lower Ct values associating with worse outcomes is worth a prospective study. Interestingly, there was no association with Ct values and common risk factors for CDI such as prior antibiotic use, suggesting that Ct values may not clarify current controversies in testing for CDI.