Opuntia was originated in tropical America, but has been introduced to other regions of the world, such as Europe (particularly the Mediterranean countries) and Africa. The genus' crassulacean acid metabolism (CAM) photosynthesis allows it to adapt to areas with diverse degrees of aridity. Its fruit is currently known as cactus pear, but is also called prickly pear, tuna and fico d'India among other names, depending on the country of cultivation. Cactus pear is a berry and is mainly consumed fresh. Bioactive compounds, such as betalains, polyphenols and dietary fibre, have recently been reported in the fruit. Many processing technologies can be used to preserve the fruit. Products include dehydrated sheets, toppings and microencapsulated juices as antioxidants and colorants. This chapter discusses the postharvest physiology, technologies and processing of cactus pear.