Selective dehydrogenation of neohexane to neohexene was carried out on platinum polymetallic catalysts at high dilution in steam to overcome severe chemical equilibrium limitations. The conversion at 550 degreesC, WHSV = 1 h(-1), and a dilution ratio of 20 was close to equilibrium values of 17%. Two catalysts, Pt-Sn-K/alumina and Pt-Sn-K-Fe/alumina, yielded similar initial performances of high selectivity of 83 mol %, significantly higher than those of supported Cr catalysts. However, fast coke formation is inherent to this process. Therefore, regeneration of the catalysts is a critical step in the process. Steam regeneration is the most practical method of regeneration if the catalyst performances can be retained for many cycles. Addition of Fe to the Pt-Sn-K/alumina catalyst yielded excellent long-term stability in steam regeneration compared with the poor behavior of the basic Pt catalyst.