This study was designed to investigate the predictive and construct validity of six experimental measures of career maturity. Six career maturity measures were constructed and administered to 11th-grade students in three schools ( n = 112, 97, 117) in the spring of 1983. One year later, criterion measures were collected from the same sample of students near the time of graduation from high school. Scores on four of the six career maturity scales were found to be consistent with theoretical expectation: they are reliable; they correlate significantly with each other; they are independent of academic achievement; and they are significantly related to at least one relevant criterion measure collected 1 year later. It was concluded that the data provide some support for the construct and predictive validity of four of the six career maturity scales. Some technical issues and possible sources of invalidity are discussed, and recommendations are made for future studies.