AIM: To explore nurses' knowledge, skills and personal attributes for competent health education practice and their association with potential influencing factors. BACKGROUND: Clinical nurses are expected to perform effective health education interventions, but they do not feel competent. The self-assessment of the health education competence and its conditional factors is paramount for professional development. DESIGN: A cross-sectional study. METHODS: A total of 458 clinical nurses from two health specialized centers in Spain participated in this study. Data were collected using the Nurse Health Education Competence Instrument and a second self-report questionnaire from January to February 2019. Descriptive statistics, t-test, analysis of variance, Pearson's and Spearman's correlation and multiple linear regression were used to analyse the data. The STROBE guideline was used RESULTS: The mean scores of the knowledge (70.10±15.11), skills (92.14±15.18) and personal attributes scales (32.32±5.89) were found to be low to moderate. The main influencing factors for the health education implementation were lack of education and training (71.4%), lack of time (67.5%) and high workload (67.3%). Nurses with higher educational level and perceived self-efficacy for competently providing health education, more extensive professional experience and previous training in health education rated higher in knowledge, skills and personal attributes. Age and years of experience were negatively correlated with knowledge scores, but positively with the rest of domains of the competence and self-efficacy. The regression models for the overall health education competence's domains were significant (p<0.001) with R2 values ranging from 28.0% to 49.3%. Self-efficacy, previous health education training and working in intensive care units were found to be significant in all cognitive, psychomotor and attitudinal scales. CONCLUSION: Clinical nurses reported on some skills and personal attributes for health education practice, but they seem to lack health education knowledge necessary for a competent practice. This study suggested that effective education and training and supportive organizational cultures are key to enhance nurses' health education competence. Identifying nurses' educational needs on the main domains of the competence and its intrinsic/extrinsic influential factors may assist in both planning and organizing tailored training strategies and in promoting appropriate environments to support a high-quality health education practice TWEETABLE ABSTRACT: Nurses' knowledge, skills and attitudes about health education competence are low to moderate. Training and organizational support are key.