Introduction Effective management of suicidality and impulsivity in hospitalized psychiatric patients is vital for improving outcomes and ensuring safety. Psychiatric patients, especially those with schizophrenia, exhibit higher tendencies towards aggressive and suicidal behaviours. This study aims to explore sex-specific associations between lipid profiles, impulsivity, and suicidality among psychiatric inpatients.Methods A total of 158 psychiatric inpatients (92 men and 66 women) were assessed using the Barratt Impulsiveness Scale, the Columbia Suicide Severity Rating Scale, and the Karolinska Interpersonal Violence Scale. Serum lipid levels (total cholesterol, LDL, HDL) were obtained from fasting blood samples.Results Among men, higher total cholesterol and LDL were positively correlated with impulsivity (LDL and BIS-11 total score: rho = .308, p = .006). In women, higher HDL was associated with lower suicidality (HDL and lifetime suicide attempt frequency: rho = -.374, p = .021). Regression confirmed LDL predicts impulsivity in men (R squared = .265, p = .031), and HDL, LDL, age, and BMI explain 52 percent of suicidality variance in women (R squared = .523, p = .0006).Conclusion Elevated LDL may indicate higher impulsivity in men, while low HDL suggests higher suicide risk in women. Lipid monitoring could enhance risk assessment in psychiatric care.