he development of a revised Strelau Temperament Inventory (STI-R) is reported. It is assumed that the STI-R provides a measure of the basic central nervous system (CNS) properties (strength of excitation, strength of inhibition, and mobility of the CNS) as understood by Pavlov. On the basis of a series of studies, the development of the final forms of the revised STI has undergone several steps. The following forms have been elaborated: (1) a 252-item pilot form of the STI-R; (2) a 166-item STI-R with ‘yes’ and ‘no’ answer format; (3) a short form (84 items) of the STI-R (STI-RS) with ‘yes’ and ‘no’ answer format; (4) a 166-item STI-R with a 4-point Likert scale; and (5) an 84-item STI-RS with a 4-point rating scale. The psychometric characteristics of the consecutive versions of the revised STI improved from step to step, and in general these characteristics are judged as being satisfactory. Especially recommended by the authors are versions (4) and (5), which have, among other things, the highest reliability scores. They are regarded as the final forms of the STI-R and STI-RS.