The effects of floor space and beak trimming on behavior and growth of Large White male turkeys were investigated Floor space allowances were 6.5, 9.3, and 12.1 dm2/bird at 0 to 8 weeks; 11.7, 16.7, and 21.8 dm3/bird at 8 to 12 weeks; and 28, 35, and 42 dm3/bird at 12 to 20 weeks. Floor space was adjusted by changing the pen size while maintaining a constant number of birds per pen. Body weight, feed intake, feed efficiency, feather score, live market quality, and mortality were measured. In addition, agonistic behavior including "threat avoids", "peck avoids", "threat chases", "peck chases" and "fights", and nonagonistic behavior including feather "pecks" and "pecks and pulls" were determined at 12 and 20 weeks of age. Floor space had no significant effect on any parameter measured through 8 weeks. At 12 weeks, feed efficiency and body weight were significantly decreased with decreasing floor space. By 20 weeks, the body weight of the birds grown at the intermediate floor space allowance from 8 to 12 weeks was no longer significantly different from those grown at the highest floor space allowance; however, the birds grown at the highest density from 8 to 12 weeks remained significantly lighter at 20 weeks. Compensatory growth, if present, appeared limited. Beak trimming had no significant effect on body weight or feed efficiency. Food intake was significantly greater in the beak trimmed birds from 12 to 18, but there was no significant difference from 12 to 20 weeks. From 12 to 20 weeks, mortality was significantly less in beak-trimmed birds.(ABSTRACT TRUNCATED AT 250 WORDS)