Abstract: OBJECTIVE To investigate the risk factors of linezolid-related hematologic toxicity in hospital patients.METHODS In this single center, observational retrospective study, main clinical characteristics of 78 inpatients undergoing therapeutic drug monitoring during linezolid therapy were reviewed. The risk factors of linezolid-related hematologic toxicity were confirmed by multivariate Logistic regression analyses.RESULTS In logistic regression analyses, the significant risk factors of linezolid-related leukopenia including duration of linezolid therapyOR=1.296(1.094-1.53), P=0.003, estimated glomerular filtration rate <30 mL·min^-1·(1.73 m²)^-1OR=11.582(1.870-71.729), P=0.008; the first trough concentration of linezolidOR=1.178(1.052-1.318), P=0.005, baseline serum albumin <30 g·L^-1OR=4.175(1.315-13.254), P=0.015 were found to be significant risk factors for linezolid-related thrombocytopenia.CONCLUSION Leukopenia is a time-dependent toxicity with linezolid, thrombocytopenia is a concentration-dependent toxicity. Patients should be closely monitored for blood routine throughout linezolid treatment. Therapeutic drug monitoring and individualized therapy may be recommended, if condition permits.