Since the introduction of the ‘upper echelon theory, a lot of research has been done on the effects of various CEO characteristics like age, tenure, educational background, functional expertise or international experience on different organizational outcomes. However, so far no research concentrated on the effect of these characteristics on a firms degree of technological diversification. Data from 1275 German manufacturing firms is used to test the hypotheses. The findings show that the CEOs age, the organizational tenure, and output functional expertise positively impact the degree of technological diversification. In contrary, the positional tenure has a significantly negative effect. Finally, the results about the educational level and international experience could not deliver any significant results.