Introduction: In pharmaceutical industry there are some possibilities of contamination and cross contamination because of improper cleaning of equipment, apparatus, processing area or the starting material, this can lead to severe hazards, therefore in pharmaceutical industry could not afford any contamination as well as cross contamination. This can be minimized by proper cleaning of equipment, apparatus as well as the processing area. The cleaning validation is a documented process that proves the effectiveness and quality prospective. Manufacturing of Diclofenac sodium (DICLOMON) retard tablets and utilizing common facility, where diclofenac sodium could be possible cross contaminant. The present study was carried out to validate the cleaning activity from both regulatory and quality prospective. Methods: All chemicals and reagents used for cleaning validation were analytical grade and used LC-20AT Shimadzu HPLC. Traditional methods were used for microbiological analysis. The instruments in the common facility were cleaned with purified water after production of Diclofenac sodium retard tablets 100mg. Validation of cleaning activity was carried out by visual inspection, swab sampling for chemical residue and similarly swab sampling for Microbiological analysis. Conclusion The cleaning validation studies of Diclofenac sodium retard tablets 100mg was observed by visual inspection, swab sampling for chemical residue and similarly swab sampling for microbiological analysis. The result revealed that (1) There were no visual residues on the equipment (2) Chemical residues were below acceptance criteria (3) Total aerobic microbial count(TAMC) were below acceptance criteria (4) Total combined molds and yeast count was Nil and (5) Pathogens were absent Upon the compiled data, it was concluded that the train of equipment in tablet manufacturing block is completed, and the results were found to be satisfactory and there is no cross contamination of Diclofenac sodium to next product.