Miltefosine (hexadecylphosphocholine), the first oral drug against visceral leishmaniasis, triggered pneumococcal autolysis at concentrations higher than 2.5 microM. Bactericidal activity was also observed in cultures of other streptococci, although these failed to undergo lysis. The autolysis elicited by miltefosine can be attributed to triggering of the pneumococcal autolysin LytA.