In the present study the effects of heat stress on the free amino acid profiles of Aloe vera and Bryophyllum pinnatum leaves were investigated. Heat stress was provided by exposing the plants to a daily temperature of 38-43 0C for one month. After heat stress the leaves were collected and dried in oven. The powdered dried leaves were used for amino acids extraction and analysis. In Aloe vera leaves 9 essential and 7 non-essential amino acids were detected, highest concentration was recorded for phenylalanine followed by arginine and valine while histidine and aspartate were present in the lowest amounts. In Bryophyllum pinnatum 8 essential and 7 non-essential amino acids were detected, glycine was recorded in highest concentrations followed by arginine and proline while lysine was observed in the lowest concentrations. The two plants accumulated different amino acids in response to heat stress. In both plant species proline and serine were accumulated while the concentration of alanine and glycine declined significantly in response to heat stress. The total essential amino acids decreased while total non-essential amino acid increased significantly in Aloe vera while in Bryophyllum pinnatum no significant effect was observed on the concentration of total essential and total non-essential amino acids in response to heat stress.