The study aimed to evaluate the effect of dietary pharmacological levels of supplementary copper on the productive performance, intestinal morphometry, hepatic copper, and copper in feces of Guinea pigs during 56 days. Sixty weaned male Guinea pigs were used for this experiment, randomly distributed into four treatments with five replicates each and three animals per replicate: T1, basal diet (0 ppm of Cu supplemented as copper sulfate); T2, basal diet + 100 ppm Cu; T3, basal diet + 200 ppm Cu; T4, basal diet + 300 ppm Cu. No significant differences were found between treatments on final body weight, daily body weight gain, voluntary feed intake, feed conversion ratio and mortality. In addition, supplemented copper caused a significantly reduction (p<0.05) of the villus height and villus height:crypt depth ratio as the level of supplemented copper increased. The copper concentration in liver and feces significantly increased (p<0.05) as the level of supplemented copper increased. It is concluded that dietary pharmacological levels of supplementary copper did not improve productive performance, increased the concentration of copper in liver and feces and showed a negative effect on intestinal morphometry.