The purpose of this study was to determine the proximate compositions, mineral contents and fatty acid compositions of chicken and turkey gizzards. In addition, the textural properties of the gizzards were determined after tenderization with sous vide cooking and proteolytic enzymes, such as bromelain, ficin, and papain. Four different groups (control, bromelain, ficin, and papain) for each gizzard species (chicken and turkey) were prepared for the tenderization part of this study. Firmness, work of shear, and collagen content of tenderized gizzards were determined. Results revealed that gizzards were a good source in terms of macro and trace elements, such as Zn and Fe. Chicken and turkey gizzards had low total saturated fatty acid content. Total monosaturated fatty acid content was found as 37.38% for chicken gizzard and 44.82% for turkey gizzard. Proteolytic enzyme treatments increased the tenderness of gizzards. Practical applications: Gizzard is one of the edible by-products in the poultry industry. It is an economical source of protein and other nutrients since it is cheaper compared to chicken and turkey meat. In this study, it was revealed that gizzard is a good source in terms of protein, macroelements, and trace elements, such as iron and zinc. Additionally, consumption of gizzard is thought to be beneficial for human health since gizzards contain lower total saturated fatty acid levels and higher total monosaturated fatty acid. However, gizzards have tough texture due to their high content of collagen. For this reason, in this study, chicken and turkey gizzards were tenderized with plant-derived proteolytic enzymes and sous vide cooking.