Calcium chloride (CaCl2) solution in concentrations of 0, 0.2, 0.3 and 0.4 M was injected at 10% (wt/wt) either 45 min or 24 h postmortem into longissimus dorsi muscles of eight draught steers discharged from work and 4 years of age. Shear force, after 7 days of aging, declined by CaCl2 injection by up to 50% of control, depending on CaCl2 concentration. Prerigor treatment was twice as efficient as postrigor injection. Collagen content and solubility were less clearly affected. Sensory tenderness scores were higher by 50% with all CaCl2 concentrations, but only with prerigor treatment. A bitter taste was noted only with the highest concentration of CaCl2, but overall acceptance did not increase with CaCl 2 concentration. CaCl2 enhanced electrical conductivity, reduced redness and luminosity, and increased drip and thawing loss, but not boiling loss, of longissiumus dorsi. Results indicate a high potential of CaCl2 treatment in extraordinarily tough meat. © 2004 Elsevier Ltd. All rights reserved.