Background Although burnout levels in oncologists are likely high, its predictors remain poorly understood. Aims This study was aimed to verify the prevalence of occupational burnout in oncology doctors and nurses in the major cancer centre in Kazakhstan and to elucidate its predictors to plan future prevention activities. Methods In the leading tertiary-level cancer centre in Kazakhstan, we recruited 256 subjects (67% doctors and 33% nurses, 62% women, median age 37.5 [interquartile range 15] years) and offered them Maslach Burnout Inventory to quantify emotional exhaustion (EE), depersonalization (DP) and personal accomplishment (PA). Demographics, fatigue, health-related quality of life with SF-8 and lifestyle were tested as predictors of burnout in multivariate logistic regression models. Results Number of subjects with high EE was 121 (47%), high DP was 161 (63%) and high PA was 152 (59%). Fatigue, worse mental component score (MCS), being single and not exercising regularly predicted more burnout in EE. Fatigue, worse physical component score (PCS) and worse MCS predicted more burnout in DP. Finally, more burnout in PA was independently associated with fatigue, worse PCS, being married or divorced and having a university or academic degree. Conclusions The prevalence of occupational burnout in oncologists was high, necessitating early burnout prevention programmes, addressing, among other, fatigue reduction and regular exercise. © The Author(s) 2021. Published by Oxford University Press on behalf of the Society of Occupational Medicine.