The present article deals with an oral dosage form proposed for the attainment of timed release drug delivery of metronidazole. Metronidazole containing matrix tablets coated with 3,4,5 & 6% w/v cellulose acetate phthalate in acetone were examined for applicability as timed release tablets with a predetermined lag time of 4-5 hrs. Different types of enteric coated tablets were prepared and there drug dissolution profile was studied in 0.1 N HCl (0 to 2hr) and PBS 6.8 (2- 24 hr) as dissolution media at 37±0.5 ºC,100 rpm by USP Apparatus-1(Basket assembly). The result indicated that the tablets with timed release functions could be prepared and,that the lag time were increased as the coat concentrations increased (3% to 6%w/v).The different kinds of timed release enteric coated tablets that showed lag time of 2 to 5.4 hrs in in- vitro dissolution in 2% w/v rat caecal content in 6.8 PBS(Phosphate buffer saline). The lag time showed a good agreement between the in- vitro test in PBS 6.8 and in -vitro test in 2% w/v rat caecal content. However the lag times were 4.5 hrs in in-vitro test in 2%w/v rat caecal content medium.