Levels of rising political distrust in the USA and parts of Europe attracted political scientists' attention in the 1990s, and urged them to look at possible consequences of this phenomenon for the functioning of democracies and social life. Approximately during the same period, from a sociological viewpoint, social capital theorists started studying the effects of declining social capital on political and economic life. In this article, we looked at the relationship between political distrust and social capital from an interdisciplinary perspective. We studied the relationship in six European countries from three regions (North-West, South and East), and the USA, and we were interested in the question of whether this relationship varies over the regions, or whether it is approximately the same everywhere. We used ISPP data from the 2004 wave, which included a range of social capital indicators and political distrust items. Social capital was subdivided into four dimensions, namely, networks (membership of organizations), interpersonal or social trust, social norms (citizenship norms), and linking social capital (political activities). First we studied the effect of political distrust on these four dimensions of social capital, while controlling for other variables such as political efficacy, political interest and a set of socio-structural background variables. One of our main findings was that the only significant effect of political distrust we found throughout all countries was a negative effect on one dimension of social capital, namely, interpersonal trust: the more people distrust politicians and people in government, the less they trust other people in general, even when controlled for all other variables. The reverse relationship led us to the same conclusion: the more people tend to trust people in general, the less they distrust politics, a result we found in all countries. This finding refutes the claim that there is no or either only a very weak relationship between political and social trust, as some have strongly argued before. Other important political attitudes connected to social capital were political interest and political efficacy, and for political distrust it was external efficacy. Significant socio-economic factors were religiousness and educational level for membership of voluntary organizations, educational level for interpersonal trust, religiousness for citizenship norms, and educational level and age for political activities. The reciprocal relationship was strongest in the USA and North-Western Europe, as were the explained variances of our (more extensive) regression models. In Southern and Eastern Europe other factors appear to be at work which influence both social capital and political distrust.