The aim of this research was to determine the success of predicitng certain facets of health-related quality of life of hemato-oncology patients in Croatia based on knowledge of the sociodemographic data of patients, the determinants of the disease, the information of patients about their disease and the quality of doctor-patient communication. A combination of „paper – pen“ and online surveys included 50 men and 54 women over the age of 18 who had been diagnosed with leukemia and/or lymphoma. For the purposes of the research, a questionnaire of sociodemographic characteristics was constructed, which collected sociodemographic data and characteristics related to the participant's disease. The construct of health-related quality of life was measured by the EORTC QLQ-C30 questionnaire, the construct of the patient information by the EORTC QLQ-INFO25 questionnaire and the construct of doctor-patient communication by the Doctor-Patient Communication Questionnaire (Sustersic et al., 2018). The results indicate a moderate level of general health status/quality of life, moderate to moderately high levels of physical, role, emotional, cognitive and social functioning, low to moderately high levels of information, and high satisfaction with doctor-patient communication. After conducting hierarchical regression, it was established that patient information, in addition to sociodemographic dana and characteristics related to the disease, statistically significantly predicts the general health status/quality of life and physical, role and social functioning. Significant predictors for general health status/quality of life were shown to be comorbidity and hospitalization frequency, for physical functioning age, information about the things patients can do to help themselves, frequency of hospitalization and comorbidity, for role functioning gender and frequency of hospitalization and for social functioning frequency of hospitalization and information about the things patients can do to help themselves. For further research, it is recommended to use a larger sample including patients from different hospitals and to use other doctor-patient communication questionnaires to understand the under–researched construct better.