Background The need for care of patients is increasing day by day as societies age. In parallel with the increase in the need for care, the adequacy of the care provided and the factors affecting it gain importance. Objective This study aims to determine the effect of nurses’ humanistic behavior skills on caregiving competence and the factors affecting it. Methods The study sample consisted of 445 nurses working in a state hospital and selected by random sampling method. The study data were collected between January and April 2023. Face-to-face interview method was used to collect the data. The questionnaire application was conducted in a period of approximately 15–20 min. The nurse information form including demographic characteristics, the humanistic behavior skills in nursing practice scale (HPAN) and the caregiving competence scale were used to collect the data. Results The nurses’ humanistic behavior skills affected their caregiving competence by 0.082. HPAN and age had an effect size of 0.084 on caregiving competence; HPAN, age and gender had an effect size of 0.124 in the triad model; HPAN, age, gender and average overtime worked in a month had an effect size of 0.136 in the quad model. Conclusions It was determined that as the humanistic behavior skills of the nurses increased, their caregiving competence also improved. The humanistic behavioral skills of the nurses affect care giving competence at a rate of 8.2%. In addition, age, gender, overtime work and working years also affect care giving competence.