The main aim of the work is to design and develop stable formulation of effervescent tablets of Paracetamol and N-Acetylcysteine and to evaluate respective formulation. The present work is directed to a new pharmaceutical formulation comprising Paracetamol and N-acetylcysteine in the form of effervescent tablet to be taken orally and offering a considerable advantage over other dosage forms.Paracetamol is an analgesic and anti-pyretic agent. It is clinically used for temporary relief of fever, minor aches, and pains. N-acetylcysteine is a mucolytic agent and also used as Paracetamol poisoning antidote. Market Survey revealed that Paracetamol and N-Acetylcysteine in combination are introduced in market as tablet and syrup dosage form. Due to the high dose and taste problems of Paracetamol and N-acetylcysteine it is difficult to formulate in film coated tablet dosage form or as syrup due to stability issues. So, Effervescent Tablets acts as an alternative dosage form. Effervescent tablets are designed to be dissolved or dispersed in water before administration. Since effervescent tablets are administrated in liquid form; they are easily swallowed so they are preferred over tablets or capsules.