Significant advances in the understanding of the cells and molecules involved in tumour/host interactions in humans have been made over the last decades. Thus, through studies of the interactions between cells of the immune system and cancer cells, several tumour antigens and their epitopes recognised by human leucocyte antigen class I-restricted cytotoxic T lymphocytes have been identified. Likewise, specialised antigen presenting cells have been characterised and methods developed that allow the use of such cells in clinical immunology. In the clinic, systemic administration of immune stimulatory cytokines, in particular IL-2, has strengthened the notion that the immune system is capable of mediating rejection of cancer. More recently, more sophisticated methods of inducing anti-cancer immune responses have been pursued, for instance the use of antigen presenting cells in combination with various sources of antigen and cytokines for therapeutic vaccinations against cancer. The present paper summarizes current knowledge in the field of tumour immunology, and reviews various approaches undertaken with the aim of inducing strong anti-tumour responses. To this end, we review data from clinical trials, and discuss the potential of these treatment modalities as an adjunct to conventional modes of cancer treatment. Further, novel methodologies for monitoring and analysing cancer patients over the course of immunotherapeutic treatments are described, and future directions put forward.