Aim: Carboplatin offers high response rates and improved overall survival for women with ovarian cancer, but treatment may be limited by carboplatin-induced HSRs. We identified patients at high risk of carboplatin-induced HSRs that could be targeted for future prevention therapies. Methods: A retrospective chart review of 452 patients with ovarian cancer receiving a sixth or subsequent cycle of carboplatin-containing chemotherapy from 2006 to 2012 at Princess Margaret Cancer Centre (PMCC) in Toronto, ON was performed. Age, cumulative number of treatment cycles, cumulative carboplatin dose, co-administered chemotherapy, BRCA status, use of prophylactic diphenhydramine and other allergies were noted. The pattern of carboplatin administration was recorded as either continuous, short (≤12 months) or long interval (>12months) since last receiving carboplatin-containing chemotherapy. Predictors of HSRs were assessed using the Chi-square, student's T-test and a multivariable logistic regression model. Results: Carboplatin-induced HSRs occurred in 9% (n = 41/452) of patients, of which 4 were anaphylactic. Their median age was 57 (range 25 to 89). Sixteen percent received carboplatin alone; the remaining patients received co-administered Paclitaxel (74.5%), Caelyx (4.2%), Gemcitabine (2.4%) or another agent (2.7%). Thirty five percent received diphenhydramine prophylaxis. Univariable predictors of carboplatin-induced HSRs included the number of carboplatin cycles, other drug allergies and the platinum-free interval. Cumulative carboplatin dose, co-administered chemotherapy, diphenhydramine prophylaxis and BRCA status were not significant. In a multivariable model, factors predictive of HSRs included the administration of 8 to 10 cycles of carboplatin [OR 7.5 (95%CI 2.8-20.1), p Conclusions: Ovarian cancer patients receiving 8 to 10 cycles of carboplatin-containing chemotherapy and those with a long interval (>12 months) since last receiving carboplatin are at an increased risk of carboplatin-induced HSRs. These patients may be targeted for future prevention therapies. Disclosure: All authors have declared no conflicts of interest.