We detected a new outbreak focus with high incidence of cutaneous leishmaniasis in the Sub Andean region of La Paz. This area was never considered previously as an endemic zone of leishmaniasis. Leishmania stocks from human lesions were isolated: three stocks were explored by pulse field gradient electrophoresis, showing evidence for their affiliation to the L. mexicana complex. Eight stocks were submitted to isoenzyme electrophoresis and compared with five reference strains: L. amazonensis, L. braziliensis, L. chagasi, L. mexicana and L. pifanoi. Close genetic proximity was evidenced between newly isolated parasites and the reference stock of L. amazonensis, whereas high divergence was observed between them and either the L. pifanoi, L. mexicana, L. braziliensis and L. chagasi reference strains.