Background: Cultural competency is particularly important in healthcare industry nowadays, where cultural beliefs have a significant impact on care access, treatment choices, effectiveness of nursing care, and other aspects of patient care. This study aimed to explore the level of cultural competency and the factors affecting the cultural competency of nurses, from two medium-size private hospitals in Bangkok, Thailand with similarity in therapeutic specialties and other characteristics in three categories: multi-cultural knowledge, attitude towards different cultures and cultural practice in nurses. Methods: This was cross sectional study by interviewing 166 nurses in two hospitals of Bangkok in December 2014. The samples were selected using proportional simple random sampling (SRS) method. The data was collected using a validated, piloted and reliable self-administered questionnaire and analyzed in SPSS 16.0 using descriptive statistics, regression and Chi-square analyses.Results: The analysis showed that the overall level of cultural competency of nurses was classified as low to moderate (75.9% of all nurses scored low multicultural knowledge competency while 63.3% and 71.7% of all nurses scored moderate attitude towards different cultures and cultural practice respectively). It was found that knowledge of different cultures was affected by responsibility, age and level of confidence of the nurses (p < .05) while attitude towards different cultures was affected by work shift, level of confidence and marital status of the nurses (p < .05). Further study showed that the level of confidence in communication and nursing care towards foreign patients and the level of attitude towards foreign patients significantly associated with the quality of cultural practice (p < .05). It was found that level of confidence and attitude had positive correlation with the cultural practice. Conclusions: Study has concluded that the good quality of cultural practice was primarily driven by the positive confidence and attitude while the expedience factors, level of knowledge and other background marginally affected the quality of cultural practice.