Beta-lactoglobulin (BLG) is the main whey protein and it is frequently used additive in wide range of food products due to its excellent techno-functional properties, high nutritional value and low cost. It is also considered as acid-resistant drug carrier for delivery of pharmaceutical and nutraceutical agents. However, BLG is the main allergen of milk. A variety of methods have been explored for modification of BLG in attempt to improve its functional properties and to decrease its allergenicity. Due to its compact globular structure BLG is relatively resistant to modifications, especially under mild conditions. BLG can be modified by physical, chemical and enzymatic treatments. Although chemical modifications offer efficient way of alteration of protein structural and functional properties, they are associated with safety concern. In the last decade there is a tendency for application of novel non-thermal physical processing methods, as well as enzymes in order to obtain BLG with desirable properties. The objective of this review is to overview chemical, physical and enzymatic processing techniques utilized to modify BLG and their effects on structure and functional properties of BLG. [Projekat Ministarstva nauke Republike Srbije, br. 172024 and FP7 RegPot project FCUB ERA GA No. 256716]