Pal and Cpl-1, two purified bacteriophage lytic enzymes, were tested for their in vitro activity, alone and in combination, against several serotypes of Streptococcus pneumoniae, including penicillin-resistant strains. The enzymes demonstrated synergism in their ability to cleave the bacterial peptidoglycan and thus may be more efficient for the prevention and elimination of pneumococcal colonization.