There is a growing interest in the use of larger group housing for grower-finisher pigs. Since most research has typically been done with smaller group sizes, there is a need to better understand the effects of increasing group sizes. The objective of this study was to determine the effects of 10, 20, 40 and 80 pigs/pen evaluated on their production and health. A total of four, twelve week trials revealed similar injury scores among group sizes. A significant difference in gain was noticed during the first six weeks with no consistent pattern. Overall, ADG was similar among groups. It was concluded that if adequate amounts of space are provided for grower/finisher pigs, the use of larger group sizes is not detrimental to the health and productivity of pigs, nor significantly different compared to smaller group sizes.