Ingestion of the larval nematode Angiostrongylus cantonensis can cause the human eosinophilic meningitis known as angiostrongyliasis. Analysis of the extracts and excretory-secretory (ES) products of A. cantonensis larvae and adult stages on gelatin substrate zymography demonstrated the presence of distinct gelatinolytic enzymes. In worm extracts, inhibitor studies showed that the metalloproteinases revealed in L(1) (23 kDa), L(3) (66, 42 and 30 kDa), young adult worm (72 and 94 kDa) and adult worm (72 and 94 kDa). In ES products, the L(1) revealed one low (42 kDa) and two high (105 and 94 kDa) molecular weight proteolytic bands that degraded gelatin in substrate gels. The L(3) revealed three low (66, 50, and 30 kDa) and one high (105 kDa) molecular weight proteolytic bands. Inhibitor studies confirmed that the 105 and 94 proteolytic bands of the L(1), and the 50 and 30 kDa proteolytic bands of the L(3) classification were metalloproteinases. These metalloproteinases secreted in the infective larvae may be associated with the parasite dissemination or pathogenesis.