A new test of personality based on Murray's need-press theory and following the lead of the Personality Research Form (PRF) was developed. The construction and validation of the Personality Adjective Inventory (PAI) is described. The instrument is composed of 100 adjectives which measure 20 traits. A Likert response format is used to increase reliability. Overall, the inventory showed excellent psychometric properties across several measures of reliability, stability, and validity. It compares favorably to other adjective inventories as well as to the PRF. Strengths, weaknesses and possible uses of the PAI were discussed.