Active listening in conversation is considered an important professional duty within nursing in general and in medical telephone advice service in particular. This can be accomplished in several ways, often by the use of minimal responses, such as in back channeling and short vocal feedback signals. The aim of this article is to explore the professional use of feedback signals in medical advice calls. Previous research has reported a variety of functions of feedback signals, both in professional contexts and in telephone calls, and such functions include continuers and empathic and channeling tokens. The results of my present study indicate that the feedback signals in telephone advice mainly belong to one of a number of information-oriented subtypes. Referential signals are the most frequent, but other commonly-used signals have regulatory, channeling, or phatic functions. Emotional- affective signals are also used, but to a less degree than in e.g. psychotherapy. The different functions can be distinguished and defined by prosodic features used in their production. Feedback signals usually appear at syntactic borders, except for empathic signals, which are uttered more freely. The signals seem to be part of a professional practice in which the nurse continuously and pedagogically adapts to the emergent situation and the caller. It is suggested that the form of feedback signals may be conventionalized to some degree, a finding that, however, needs to be further explored.