The objective of this study was to attempt to develop an index of assessment items important to most, if not all, mental capacity determinations. A group process, judgmental method was used. Three separate panels of multidisciplinary experts were assembled to define relevant assessment items and to assign importance weights to the items. All three panels generated a list of assessment items, but panelists refused to assign importance weights. Four items were identified by all three panels, six were identified by two panels, and three were identified by one panel only. A composite list of mental capacity assessment items was generated, but the study failed to generate a standardized assessment instrument.