Objective Interprofessional collaboration is considered an important strategy in overcoming the complex issues associated with healthcare outcomes. A nationwide, community-based integrated care system developed for the care of older people in individual communities in Japan requires community hospitals to deliver integrated care to coordinate efforts for creating effective environments for health. This study aimed to explore the factors associated with the self-assessment score of interprofessional collaboration in community hospitals. Design Cross-sectional study using the Assessment of Interprofessional Team Collaboration Scale (AITCS). Setting This study was conducted in three small community hospitals in Japan. Participants All healthcare staff in the hospitals via research collaborators were asked to complete the anonymous self-administered questionnaire of the AITCS comprising questions related to individual factors (age, gender, profession), hospital to which they belonged, relationships with neighbouring facilities, job burden and job satisfaction from July to October 2018. The association between the questionnaire items as explanatory variables and AITCS score as an objective variable was determined using univariate followed by multiple regression analyses. Results The data from 325 of 630 participants were analysed, of whom 252 were female (77.5%) and 240 were nurses (73.8%). The mean of the total AITCS score was 117.6 (range 37-185), and the Visual Analogue Scale for relationships with neighbouring facilities, job satisfaction and job burden was 53.0mm (0-100), 46.1 mm (0-100) and 64.3mm (0-100), respectively. In univariate analyses of the association with AITCS score, explanatory variables with a significance level of <0.05 were relationships with neighbouring facilities, job satisfaction and job burden. On multiple regression analysis, the total AITCS score was independently associated with age, profession (nurse/non-nurse), relationships with neighbouring facilities and job satisfaction. Conclusions Better self-assessment score of interprofessional collaboration is more strongly associated with younger age, a nursing profession, better relationships with neighbouring facilities and greater job satisfaction than with the hospital to which the participant belonged. These findings may help community hospitals enhance the integration of service delivery and benefit to the community through interprofessional collaboration.