This is a report on the first meeting of the sixth NCGIA research initiative, entitled "Spatial Decision Support Systems." This meeting, held in Santa Barbara between March 14th and 18th, 1990, was attended by representatives of the NCGIA, university faculties from Canada, the UK and the US, government agencies in Canada and the US, and representatives of Canadian and US companies. The contents of this report are compiled from the notes of the organizers, materials prepared during the meeting and the personal notes of several of the participants.