This is a phenomenologically grounded ethnographic study of the life-world of ecstasy users in the socio-cultural contexts of raving and clubs in Sydney, Australia. The thesis espouses existential-phenomenology as a framework for describing and understanding these experiences. I argue against and reject the widespread mechanistic-materialist paradigms that inform bio-medical and bio-psychological interpretations of drug-use and non-ordinary states of consciousness. As an alternative to these dominant reductionist perspectives I draw on a holistic organismic approach and the application of phenomenology to ethnographic field research. More specifically, my exploration of the experiences of ecstasy is based upon a dialogal phenomenology which enabled me to generate a processual morphology of the varieties of ecstasy experience and the users' mode of being-in-the-world. Through this endeavour I also argue for a phenomenological foundation of the study of drug-use and non-ordinary states of consciousness in general.