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On the central Alaska Peninsula 344 different brown bears (Ursus arctos L.) were measured during 502 captures in 5 spring seasons, 1970-75. Height at shoulder, chest girth, total body length, body length, neck circumference, hind-foot length, zygomatic width, skull length, total skull size, and body weight were measured and classified by sex and cementum age. Growth rates were plotted. No morphometric differences were detected between sexes at 6 months of age, but sexual dimorphism was evident by 1.5 years of age and persisted through life. Except for zygomatic width, female bears attained at least 95 percent of ultimate body dimensions between ages 4 and 6 years and males between ages 6 and 8 years. Zygomatic width was the last dimension to attain ultimate size. Extensive size overlap was demonstrated among bears 1.5 years and older of the same sex. Superior size-weight correlations were derived from zygomatic width. It was demonstrated that the sex of bears over 9 years of age could be determined on the basis of total skull size. Serial measurements of adult bears were tested for accuracy of repetitive measurements. Skull dimensions were the least affected by inaccuracies in measuring technique. Correlations (r2) for models tested revealed that skull dimensions were the best indicators of growth rate. Of the 10 dimensions studied, none provided a reliable age substitute for counting cemental annuli.