This article begins by briefly discussing some basic existential themes such as existence, phenomenology, freedom, choice, responsibility, authenticity, participation, anxiety, morality and mortality. It then goes on to look at how existentialists and psychotherapists often deal with similar constructs in coming to an understanding of the human condition. The relevance of existentialism to psychotherapy in general is then discussed, before going on to demonstrate the many conceptual similarities between existentialism and constructivist psychotherapy. Finally, some limitations to existentialist constructs are pinpointed. It is concluded, nevertheless, that existentialism has made a significant contribution to psychotherapy-especially constructivist psychotherapy.