We have completed a study of the ferromagnetic-paramagnetic phase transition (Curie transition) and the α-&ggr; phase transition in iron by differential thermal analysis. The investigation was carried out in a piston-cylinder apparatus to 53 kbar. A low-friction cell was employed that allowed the phase transitions to be detected by monitoring the change in compressibility. The ferromagnetic-paramagnetic phase boundary was found to have a small negative slope and to intersect the α-&ggr; phase boundary in a triple point at 20¿1.2 kbar. The precision of the measurements is discussed.