The zirconium isotope 93Zr is a long-lived pure beta-particle-emitting radionuclide, which is produced by nuclear fission and neutron activation of the stable isotope 92Zr. This element is a constituent of the structural components of nuclear reactor vessels. A selective liquid-liquid extraction method for radiochemical separation of Zr, based on liquid-liquid extraction with 1-(2'-thenoyl)-3,3,3-trifluoroacetone in xylene and a subsequent stripping of 93Zr by an aqueous acid solution, has been developed. The method was utilised to separate Zr from other pure beta-particle and beta-gamma emitters in different kinds of samples. Decontamination factors higher than 99% for the pure beta-particle and beta-gamma emitters and an overall chemical yield of 80% were obtained. The sensitivity of the method allows the determination of the isolated 93Zr by liquid scintillation counting and the minimum detectable activity value obtained was 0.067 Bq over a counting period of 60 min.