The primary purpose of this study was to ascertain the relationship between the occupational experience and professional preparation of machine-trades teachers and the achievement of machine-trades students taught by these teachers. Data were obtained through a mailed information form involving 46 teachers from six states and the achievement test scores of 510 junior students. Multiple regression analysis, encompassing selected teacher characteristics, was employed to predict student achievement on the three test segments of the Ohio Machine Trades Achievement Test. Analysis of variance was utilized to test achievement differences of students who had trades-trained teachers and students who had institutionally-trained teachers with trade experience. Specific conclusions were that: (1) A student's native intelligence was the vital element in predicting student achievement on each test segment, (2) The increase in machine-trades industrial experience was related to greater student achievement on respective test segments, and (3) The teacher's college credit hours beyong minimal level appear to be unrelated to greater student achievement. (Author/GEB)