Background: Schizophrenia (SZ) patients have been reported to have comorbid suicidal behavior (SB) and impaired glucose metabolism in early psychosis, but it is unclear whether impaired glucose metabolism plays a role in the occurrence of SB in patients with first-episode drug-na & iuml;ve (FEDN) SZ. Therefore, our main aim was to examine the relationship between SB and glucose metabolism in FEDN SZ patients.Methods: We recruited 319 FEDN SZ patients and collected information on their sociodemographic characteristics, clinical data, and glucose metabolism parameters. Participants' psychotic and depressive symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS) and the Hamilton Depression Rating Scale (HAMD), respectively. Fasting plasma glucose and insulin levels were also measured.Results: The percentage of FEDN SZ patients with SB was 45.5% (145/319). Compared to SZ patients without SB, SZ patients with SB exhibited higher scores on HAMD, PANSS positive subscale, as well as higher levels of fasting plasma glucose, fasting plasma insulin, and homeostasis model assessment of insulin resistance index (all p<0.05). Logistic regression analysis indicated that increased levels of insulin resistance (adjusted OR = 1.920), body mass index (adjusted OR = 0.931), and PANSS general psychopathology (adjusted OR = 1.041) were independently associated with SB. The Receiver Operating Characteristic Curve showed an Area Under Curve value of 0.732 for the combination of three factors in regression model to distinguish between SB and non-SB.Conclusions: Our results indicate that fasting glucose, fasting insulin, and insulin resistance are strongly associated with SB in FEDN SZ patients, suggesting that glucose metabolism abnormalities may be potential biomarkers of SB in SZ patients. Regular monitoring of glucose metabolism variables is essential for suicide prevention.