To identify independent factors for predicting loneliness in patients with hematological malignancies. It is an observational cross-sectional study. 157 patients with hematologic malignancies were enrolled between March 2020 and May 2020. The sociodemographic characteristics and psychometric properties (coping styles, self-esteem, big 5 personality traits, and hope) were tested for correlation with loneliness. Multivariate hierarchical regression analysis was then utilized to identify independent risk factors for loneliness. The patients exhibited a mean global score of 36.25 that corresponded to a moderate degree of loneliness. The sociodemographic factors, including occupation, family earning, living areas, times of hospitalization, were significantly related to loneliness. In addition, the coping styles, levels of self-esteem, the big 5 personality traits, and levels of hope were significantly correlated with the degrees of loneliness. Furthermore, sociodemographic factors (occupation) and psychometric properties (coping styles and hope) were identified as independent predictors for loneliness in patients with hematological malignancies. Loneliness is highly prevalent in patients with hematological malignancies. Notably, occupation, times of hospitalization, family earning, coping styles, self-esteem, big 5 personality traits, and hope are all independent risk factors for loneliness.Abbreviations: HHI = the herth hope index, PCS = positive coping style, SCSQ = the simplified coping style questionnaire, SD = standard deviation, SES = self-esteem scale, UCLA = university of California at Los Angels.