The effect of the minor elements P, S, and C on the distribution coefficients of Ir, Ge, Ga, Au, Cu, and Cr between the solid and liquid phases in Fe-Ni alloys was measured experimentally. Distribution coefficients for Ir, Ga, and Au increase with increasing P content while the distribution coefficients for Ir, Ge, and Ni increase with increasing C and S contents. For Ge, the distribution coefficient exceeds 1.0 when the P or C content of the solid exceeds 0.4 or 0.9 wt% respectively, or the S content of the liquid exceeds 7 wt%. The measured distribution coefficients were used in a solidification model of a parent body core. The model assumes fractional crystallization in which the distribution coefficients vary with composition and predicts the trace element distributions in the major iron meteorite groups. The model correctly predicts the observed trends for P vs. Ni and Au vs. Ni in the iron meteorite groups considered. Although the calculated trends for Ir vs. Ni and for Ge vs. Ni are relatively satisfactory for groups IVA and IVB, they fail to produce the observed trends for groups IIAB and IIIAB. Interelement effects of S and C on the distribution coefficients may explain these inconsistencies.