Lack of insight is a frequent concomitant of psychosis and has traditionally been viewed as a binary, all or none phenomenon. Recent conceptualization has formulated insight as a continuum representing the juxtaposition of 3 factors--awareness of illness, need for treatment and attribution of symptoms. Measurement of insight has been exclusively based on interview; this method does not easily lend itself to frequent repeated measurement and requires interrater reliability to be established. A self-report Insight Scale is presented, and evidence in support of its reliability, validity and sensitivity is provided that includes a sample of 30 patients monitored during recovery from an acute psychosis. The scale is a quick and acceptable measure that may find application in investigations of acute care, cognitive therapy of psychotic symptoms and as a method of augmenting clinical judgements of insight.