Oxaliplatin(L-OHP)-related hypersensitivity reactions(HSRs)may be fatal due to bronchospasm, dyspnea, and hypotension. Therefore, management of HSRs is extremely important, and a prompt and appropriate response is required when HSRs develop. To clarify the importance of early detection and an appropriate initial response to HSRs, we retrospectively investigated the expression of HSRs and subsequent response in patients using L-OHP from April 2016 to December 2017 at the outpatient chemotherapy center of Nagasaki Medical Center. HSRs were observed in 14/155 cases(one case of Grade 1 HSRs and 13 cases of Grade 2 HSRs). No significant risk factors were identified in individuals with and without HSRs. HSRs devel- oped following a median of 7.9(2-11)courses of chemotherapy and a median 687.8(75.4-960.2)mg/m2 cumulative dose. Half of the patients were able to recognize the hypersensitivity early by themselves. Furthermore, nurses were able to implement an appropriate initial response. Early detection and an appropriate early response to HSRs can possibly prevent the severity of symptoms.