Onion is one of the most important vegetable crops grown in all countries. In Egypt, onion is a major export crop. The total cultivated area of onion is about 146336 feddan (61485.7 ha). This area produced about 1.9 million Mg .The aim of the present study is to design, fabricate and evaluate an onion peeling machine to be used in small and medium production units, such as restaurants, hotels and small onion drying units. It could be used for large production units with some modifications, such as onion drying factories.An onion peeler was evaluated. Some physical properties of onion related to peeling process were determined. Peeler productivity, peeling efficiency index, actual peeling efficiency, the removed peels percentage, the onion mechanical injury and energy requirements as affected by onion bulb size, drum rotational speed, peeling residence time and batch load were investigated. The peeler performance was improved by adding water and air pressure systems; the peeler was also evaluated under the same previous operational parameters. Economical assessment of the onion peeling machine was carried out to determine the final peeling cost at different operational parameters.