The purpose of the present study was to develop an environmental assessment tool related to the living of the mentally disabled and to examine the health care professionals' perception of the current situations and its importance. The relationships between the current and ideal environmental situations were analyzed. The survey was conducted at 3310 municipalities nationwide by mailing self-report questionnaires, which consisted of 52 items developed by specialists for the mentally disabled and their families. The 52-item questionnaire was rated with a five-point scale for both current and important environmental situations. The main findings included statistically significant differences between the mean scores of the current and important environmental situations, items perceived as important at a similar degree, and those suggesting the largest gap between the current and important situations related to learning opportunities. These results could be useful for implementation in community health nursing.