The efficiency of four  disinfectants.( lizol, domex, phenyl (Black cat) and stericlean ) was tested against two gram positive (one S aureus ATCC 6538 strain and one clinical isolate of S aureus) and seven gram negative (one ATCC strain i.e. Vibrio cholerae ATCC 210 and six clinical isolates) organisms by phenol coefficient method (Rideal-Walker method, 1903) ; so far the standard test for evaluating most antiseptics and disinfectants of household use. It was observed that all the disinfectants used were highly effective against S. aureus ATCC 6538 and less so for S. aureus clinical isolates. Again out of all the gram negative organisms tested lizol was highly effective against Shigella flexneri and less as to others. Out of the gram negative organisms tested, when a comparative study was made, domex was found to be less effective against Proteus mirabilis and highly effective against Salmonella typhi. Phenyle (black cat) was highly effective against Shigella flexneri and less effective to Klebsiella pneumoniae but stericlean was more effective towards Proteus mirabilis and less so against Pseudomonas aeruginosa.