The atomic abundance of Zr has been established at 16± 5 Zr atoms/10 6 Si atoms in seventeen ordinary chondrites, which agrees well with Aller's (1962) solar value of 14 Zr atoms/10 6 Si atoms. Apparently, fractionation of Zr has occurred within the chondritic family, since 22 ± 3 Zr atoms/10 6 Si atoms were observed in seven Type II and Type III carbonacceous chondrites. Zr has been enriched in four Ca-rich achondrites by a factor of five, which is consistent with other trace-element enrichments. Zr may be depleted in Ca-poor achondrites and pallasitic olivines. The low Zr abundance in chondrites, coupled with Rb, Sr, Y and Mo chondritic abundances, indicates ~50 per cent enhancement of the odd-A mass distribution at A = 89 due to the neutron-shell closure. Abundance values of Zr and other nearby elements indicate Fe 56 seed nuclei were exposed to different neutron fluxes. The atomic ratio Zr/Hf of 100 in meteorites compared with 106 in the terrestrial crust indicates no serious fractionation between these two very similar chemical elements.