Abstract This study investigates the isolation and characterization of bromelain extract from the wastes of Nang Lae and Phu Lae pineapple cultivars (economical fruits of Chiang Rai province, Thailand). The waste portions such as the peel, core, stem and crown were 29–40%, 9–10%, 2–5% and 2–4% (w/w), respectively. The extract of crown from both cultivars gave the highest proteolytic activity and protein contents, while the extract from the stem exhibited the lowest values. SDS–PAGE showed that the major protein band in the extracts was ∼28 kDa. Activity staining of the crown extracts from both cultivars confirmed that the major protein band showed caseinolytic activity on the casein substrate-gel. All of the crude extracts from both cultivars gave high caseinolytic activity (>80% relative) in a board pH range (3–9). The optimum temperatures for all crude extracts were about 50–60 °C. This study founded that there is much added value into local Thailand pineapple wastes because of bromelain extraction.