This paper investigates the relationship between institutional trust in the health-care system, i.e. an institutional aspect of social capital, and self-rated health, and whether the strength of this association is affected by access to health-care services. The 2004 public health survey in the Scania region of Sweden is a cross-sectional study; a total of 27,963 respondents aged 18-80 years answered a postal questionnaire, which represents 59% of the random sample. Logistic regression model was used to investigate the association between institutional trust and self-rated health. Multivariate analyses of self-rated health were performed in order to investigate the importance of possible confounders (age, country of origin, education, economic stress, generalized trust in other people, and care-seeking behaviour) on this association. A 28.7% proportion of the men and 33.2% of the women reported poor self-rated health. A total of 15.0% and 58.3% of the respondents reported "very high" and "rather high" trust in the health-care system, respectively. Almost one-third of all respondents reported low institutional trust. Respondents born outside Sweden, with low/medium education, low generalized trust and low institutional trust had significantly higher odds ratios of poor self-rated health. Multiple adjustments for age, country of origin, education, economic stress, and horizontal trust had some effect on the significant relationship between institutional trust and poor self-rated health, for both men and women, but the additional introduction of care-seeking behaviour in the model substantially reduced the odds ratios. In conclusion, low trust in the health-care system is associated with poor self-rated health. This association may be partly mediated by "not seeking health care when needed". However, this is a cross-sectional exploratory study and the causality may go in both directions.