Abstract: Two experiments were conducted to investigate the effects of added copper on pig performance, tissue copper concentrations and fecal copper excretion. In experiment one, 18 crossbred (Yorkshire x Landrace) barrows weighing an average of 14.27±1.39 kg were housed in stainless metabolism cages for 14 weeks and fed one of three corn-soybean meal based diets (n=6) supplemented with either 0, 125 or 250 ppm copper from copper sulfate. The total fecal collection method was used to calculate daily fecal copper excretion. All pigs were slaughtered and samples of tissue were collected from the central right liver lobe, left kidney cortex and left longissimus muscle at the 10th rib. Copper excretion increased with increasing levels of dietary copper addition (p<0.01) and with the age of the pigs (p<0.01). Copper levels in muscle, kidney and liver were significantly (p<0.01) higher for pigs fed 250 ppm copper compared with pigs fed 0 or 125 ppm copper. In experiment two, 126 crossbred (Yorkshire x Landrace) barrows weighing 13.06±1.36 kg were used in a 3 x 3 factorial experiment in which the pigs were fed diets supplemented with 0, 125 or 250 ppm copper fed in the form of either copper sulfate, copper methionine or tribasic copper chloride for 24 days. The pigs were housed in groups of three with six pens of pigs fed each diet. During the first 12 days of the experiment, pigs fed tribasic copper chloride had significantly improved feed conversion compared with pigs fed copper sulfate or copper methionine. However, during the next 12 days and overall, there was no difference in daily gain, feed intake or feed conversion for pigs fed the three copper sources. Over the 24-day experiment, pigs fed 125 ppm copper had the highest weight gain (p=0.03) while pigs fed 250 ppm copper had the best feed conversion (p<0.01). Fecal copper was highest for pigs fed tribasic copper chloride (p=0.02). Fecal copper levels increased with increasing level of dietary copper (p<0.01). The overall results of this experiment indicate little difference in the performance of pigs fed copper sulfate, copper methionine or tribasic copper chloride. From an environmental standpoint, there may be advantages to choosing copper sulfate or copper methionine as these sources resulted in lower fecal copper excretion than tribasic copper chloride.