A short history of research into the study of leadership up to and including an explanation of Fiedler's (1967) contingency model of leadership effectiveness is presented. Some doubt is raised as regards the validity of Fiedler's two measures of leadership style (A.So. and L.P.C. Scores) and a comparison between the two is attempted. Five groups of leaders (total N of 14) completed Fiedler's standardised measures of leadership style and scores for the two styles, measured by the A.So and L.P.C. were computed. A comparison between both sets of scores and between mean scores for each group suggested that, contrary to Fiedler's prediction, A.So. did not behave significantly similarly to L.P.C. with A.So. Score appearing to differentiate leadership styles in the generally expected direction whilst L.P.C. Score failed to differentiate leadership styles.