Background: Immune checkpoint inhibitors (ICIs) have been one of the most significant developments in Oncology over the last decade. Despite being very effective for certain patient subsets, they have a unique side effect profile different from conventional chemotherapy that can manifest as immune-related adverse events (IRAEs). With increasing ICI use, clinicians will increasingly encounter these adverse events and thus, adequate knowledge on recognition and management of IRAEs is very important. Methods: To assess physician knowledge on IRAEs of ICIs, an online survey was administered to resident physicians in internal medicine (IM), emergency medicine (EM) and family medicine (FM) as well as to faculty physicians in IM, and FM at 3 tertiary care hospitals in Indiana. Results: We sent the survey to 413 physicians out of which 155 responded with a response rate of 38%. Out of 155 physicians, 110 were residents and 45 were faculty (27 hospitalists and 17 primary care physicians). Pembrolizumab was identified as a checkpoint inhibitor correctly by 79% of physicians, nivolumab by 64% and ipilimumab by 55%. Twenty-five percent of physicians incorrectly believed infliximab and adalimumab were ICIs. Most physicians (93%) were able to identify the gastrointestinal tract as an IRAE site whereas only 57% and 67% were able to identify cardiovascular and renal systems as an IRAE site, respectively. Fifty-nine percent of physicians believed steroids negatively affect efficacy of ICIs and should be used with caution to treat IRAEs. Sixty-five percent of physicians incorrectly thought endocrinopathies due to IRAEs are usually reversible. Most physicians (79%) believed IRAEs most commonly manifest in the first 6 months of treatment. Forty-five percent of FM residents considered antibiotics as the mainstay of treatment in ICI associated immune mediated colitis; this was significantly different from EM (15%) and IM (8%) residents(p = 0.0004). When comparing between residency programs, on a scale of 0-100, IM residents felt significantly more comfortable identifying IRAEs secondary to ICIs (27.1±24.2) when compared to EM (12.2±12.7) and FM residents (9.4±13.8; p = 0.0009). There was no significant difference among IM (19.8±20.1), EM (11.9±13.6), and FM residents (11.6±18.9; p = 0.11) when comparing how comfortable they were in treating IRAEs. When asked what the best way would be to learn about IRAEs, 36% chose printed material and algorithms, 30% picked online teaching module and 30% chose one time in-person lecture from an Oncologist. Conclusions: Resident and faculty physicians in multiple specialties are not comfortable in the management and treatment of IRAEs due to ICIs. Given that most of these physicians are usually the first point of contact with patients, physician education on identification and treatment of IRAEs is needed. Early detection of these toxicities is critical for their resolution.