Abstract- Background- Congenital heart diseases (CHD) are major congenital anomaly that are present during birth. Repair and corrective surgeries are performed as a line of treatment and is followed by chest physiotherapy(CPT) to prevent any pulmonary complication. Lung Recruitment manoeuvres (LRM) is an intervention mostly performed by anaesthetic or respiratory therapist to recruit the alveoli that are expandable and to reduce the area of atelectasis and increase the exchange of gases for patients on mechanical ventilation. Comprehensive literature search was done and have not come across any studies showing the efficacy of combined lung recruitment manoeuvre [LRM] and [CPT]. So study was conducted with aim to compare the effect of LRM as an adjunct to CPT in post- operative paediatric CHD patients on mechanical ventilation. A RCT. Methodology-The design is randomised, parallel Superiority group, assessor-blinded, controlled trial in postoperative paediatric congenital heart disease patients on Mechanical Ventilator. The study aims to answer the research question comparing standard(conventional)CPT with combined standard CPT along with lung recruitment manoeuver. The study will include 128 Post operated paediatric CHD patients on Mechanical ventilation for more than 6 hrs with inclusion criteria 0f operated case of CHD with the age group of 2-14 years intubated more than 6 hours. Subjects were grouped into two groups. Group A –Control Group [CPT] and Group B – Experimental Group [CPT along with LRM Group]. Patients were assessed pre-treatment and 15 minutes post treatment on various outcomes. Expected Results - The trial can generate the evidence for lung recruitment manoeuver as an additional to conventional CPT in terms of safety and efficacy. If the finding of the study are positive for LRT then it will be utilized to improve the patient care in postoperative paediatric CHD patients on mechanical ventilator decrease in morbidity, & stay in the ICU will be observed.