The present invention discloses a stable biocidal composition with enhanced antifungal activity at low concentration of active (s) and a process for preparing the same. The composition comprises: zinc pyrithione, C8-C18 quaternary ammonium salt (preferably cetylpyridinium chloride), water miscible glycol/polyol/glycol ether/lactam, organic amine and/or alkanol amine. The composition can be formulated into: hair care formulations, antidandruff hair care formulations, water based paints, coatings, adhesives, hard surface cleaners, fabric care compositions, wood products, plastic products and medical products. The biocidal compositions and the resulting formulations are transparent or opaque and are stable at varying pH and humidity conditions.