In follow-up studies of telephone crisis centres the clients who choose to remain anonymous cannot be included in any follow-up group. It is therefore important to try to determine if there are some ways in which the anonymous group is unrepresentative of the total sample. The results of this study indicate that tha anonymous group tend to be more lonely and more likely to withhold information than the non-anonymous group. However, it would seem that follow-up studies would not be seriously invalidated by the non-availability of the anonymous group. A possible explanation of the role of anonymity in suicidal calls is presented, and the results are further discussed in terms of a counselling approach for anonymous suicidal callers and implications for further research.