Many see trust as an important social resource for the welfare of individuals as well as nations. It is therefore important to be able to identify trust and explain its sources. Cross-country survey analysis has been an important tool in this respect, and often one single variable is used to identify social trust understood as trust in strangers, namely: "Generally speaking, would you say that most people can be trusted or that you can't be too careful in dealing with people?" The question, however, is whether this variable captures the meaning of social trust equally well in all countries. This is investigated by comparing different measurements of trust across five clusters of countries in all parts of the world. The analysis shows that there are considerable problems associated with the use of the variable of "most can be trusted" as an indicator of trust in strangers, both in terms of strangers understood as "people you meet for the first time" and in terms of strangers understood as people of a different nationality and religion. These results question the validity of previous investigations of social trust based on international survey material. The analysis furthermore reveals that a new survey question about trust in people one is meeting for the first time is better suited as indicator of social trust in comparative analysis.