Objectives  There are only a few quantitative studies focusing on religious and cultural barriers among non-Japanese-speaking patients and discussing the association in Japanese healthcare institutions. This study aims to clarify the association between the religious and cultural backgrounds of non-Japanese-speaking patients and their difficult experiences in the healthcare institutions.Methods  The Google Forms questionnaire survey was conducted in four languages (Plain Japanese, English, Chinese, Vietnamese) among non-Japanese-speaking patients who had visited a Japanese healthcare institution. Of the 376 respondents (response rate: 19.7%), 350 were included in the analysis while excluding invalid responses. The association between their religions and difficulties were examined by logistic regression analysis with putting their gender, age, Japanese language proficiency, the purpose of visit and the way to communicate in examination rooms as adjustment variables. Results  237 (67.7%) had no religion, 29 (8.3%) were Christian, 12 (3.4%) were Muslim, 22 (6.3%) were Hindu and 50 (14.3%) were Buddhist of those analyzed. Odds ratios for experiencing difficulties were significantly higher for Hindu (odds ratio ［95% confidence interval］＝6.35［1.51-26.77］) and Christian (3.67［1.27-10.61］) compared with those who do not have religion. Regarding difficulties, it was found that the half of Hindu respondents identified “food” (50%) indicating a religious and cultural background, while various difficulties were identified for Christian respondents including “religion” (22%), “culture” (22%), and “medical costs” (22%).Conclusions  This study demonstrated an association between religion and difficulties in Japanese healthcare institutions among non-Japanese patients with a large proportion of outpatients. It was observed that Christian and Hindu respondents were more likely to have difficult experiences in the healthcare institutions. The results of this study suggest a need for religious and cultural consideration in outpatient settings such as the use of healthcare interpreters and the practice of transcultural nursing by medical professionals.