Fluoride, calcium, and phosphorus content as well as ash percentage and ash density of primary antlers and pedicle bones were studied in nine yearling red deer stags from a fluoride polluted region in North Bohemia (Czech Republic) and in nine control animals from two uncontaminated areas in West Germany. Fluoride levels in antlers (845 +/- 257 mgF-/kg ash, mean +/- SD) and pedicles (1,448 +/- 461 mgF-/kg ash) of the N-Bohemian specimens exceeded that of the controls (antlers: 206 +/- 124 mg F-/kg ash, pedicles:322 +/- 157 mg F-/kg ash) by factors of 4.1 and 4.5,respectively. Antler and pedicle fluoride concentrations of the deer(n = 18) were closely correlated (r = 0.975,p < 0.001). Analyses of ash percentage and ash density revealed that theantlers of the N-Bohemian deer contained significantly less mineral and were significantly less dense than both their pedicles and the control antlers. In the pooled antler samples (n = 18), bone fluoride concentration was negatively correlated with ash density (r = -0.826, p < 0.001)and ash percentage (r = -0.759, p < 0.001), whereas nonsignificant, positive correlations existed for the pooled pedicle samples. Ash percentage and ash density of the antlers and their corresponding pedicles were uncorrelated. It is concluded that increased fluoride exposure of deer leads to reduced mineral content and mineral density of antler bone and that it is the rapidity of their growth and mineralization that makes antlers especially susceptible to fluoride action. Due to their ability to accumulate high amounts of fluoride during a defined, limited timespan and the apparently dose-dependent negative effect of fluoride on their density and mineral content, (primary) antlers can be recommended as monitoring tools for studying environmental pollution by fluorides.