In this study, the effect of cooling rate (0,27 - 7,38 - 14,23 - 21,56 degrees C/s), mold rotation speed (160 - 225 - 275 rpm), and casting atmosphere (air - vacuum) on hardness of Al-Cu functionally graded materials (FGMs) were investigated. According to the experimental results, it was found that the hardness value became higher with increasing cooling rate and efficiency of other parameters varied according to cooling rate. The hardness increased with increasing mold rotation speed and hardness values of specimens produced in air atmosphere are higher than that of manufactured in vacuum atmosphere for all parts of specimens produced in high (7,38 - 14,23 - 21,56 degrees C/s) cooling rates. On the other hand, the specimens produced in low cooling rate (0,27 degrees C/s) have varying hardness values depending on the location of the cast part. Hardness increased with increasing mold rotation speed in the far part of specimens to the rotation axis. It remained unchanged in middle section and decreased with increasing mold rotation speed in parts close to the rotation axis. Also, hardness values of specimens obtained in air atmosphere are lower in far part, same in middle and higher in rotation axis by comparison with the specimens obtained in vacuum atmosphere. Results showed that all parameters affected each other and the hardness in fabrication of FGMs by centrifugal casting.