Several aspects of the phase diagram of iron near the a-&ggr;-ϵ triple point are uncertain. Although many investigators agree about the position of the &ggr;-ϵ boundary, a wide range of values have been reported for the α-&ggr;-ϵ triple point. There is disagreement about even the sign of the slope of the α-ϵ boundary. Analysis of new P-V-T data for &ggr;-Fe, known features of the α-β phase boundary at lower pressures, the magnetic properties of several iron phases, and nonhydrostatic stresses in various high-pressure cells suggest that magnetoelastic effects in α-Fe contribute to these apparent discrepancies. Experiments which control these effects are needed to define the equilibrium values of the α-&ggr;-ϵ triple point and the α-ϵ boundary. Uncertainties about these magnetic contributions to published thermodynamic properties of iron must be carefully taken into account when measurements made near the α-&ggr;-ϵ triple point are extrapolated to estimate properties at higher pressures. ¿ American Geophysical Union 1990