The nature and distribution of precipitates in Fe-doped InP crystals grown by metalorganic vapor phase epitaxy at 650°C are studied by transmission electron microscopy. The precipitates are spherical in shape, 4-20 nm in diameter, and uniformly distributed in the crystals. They are coherent FeP precipitates with certain orientation relationship to the InP. The precipitates are observed in crystals with Fe-doping gas flow rates of more than 20 ml/min. Their density increases from 8 × 1012 to 1 × 1014 cm-3, as the gas flow rate increases from 20-100 ml/min, while the size is almost constant. In crystals doped with less than 5 ml/min, precipitates are not observed. Crystals grown with a gas flow rate of 5 ml/min contain a Fe-concentration of about 1017 cm−3 which is the solubility limit of Fe in InP at 650°C. From these results, it is strongly suggested that when the doped Fe concentration exceeds the solubility limit, excess Fe atoms tend to condense in the matrix forming FeP precipitates.