Introduction: Stevens Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are rare cases but can be life-threatening if not immediately treated. Basic knowledge about SJS and TEN is crucial for doctors so the incidence can be prevented, however the study about SJS and TEN in Indonesia is still minimal. Thus, we aim to analyze the risk factors for SJS and TEN in Dr. Soetomo General Hospital Surabaya period of 2017-2020. Methods: This was a retrospective analytical observational study with case control design using total sampling from medical records data in 2017-2020. Risk factors for sex, age, infection, and comorbidities were analyzed with bivariate and multivariate analysis. Results: From a total 28 sample cases, most sex was man (53.57%), but there was no significant effect against SJS/TEN (p=1.000). Most ages were 26?45 & 46?65 years old (39.29%). There was no significant effect between age and SJS/TEN (p=0.789). Infection that was reported only pneumonia (21.43%) and apparently there was significant correlation against SJS/TEN (p=0.023). Highest comorbidity was conjunctivitis (25%). Highest number of drugs suspected to cause SJS/TEN was carbamazepine (20%), paracetamol (20%), and phenytoin (15.56%). Conclusion: Sex, age, infection, and comorbidities are risk factors for SJS and TEN, however in this study, factor that influence the occurrence of SJS/TEN is infection by Mycoplasma pneumoniae.