Introduction Patients in icu who are critically sick require basic life support in form of mechanical ventilator. Ventilator associated complication are common in them . Prediction of icu acquired weakness can prevent extubation failure, decrease in hospital mortality and increase icu free day. Thereby decreasing financial burden . Both central and peripheral muscle thickness play role in predicting extubation success. Aim/Objective :Aim is to measure muscle strength of diaphragm and quadriceps muscle using ultrasonography and to find if central and peripheral muscle strength can be used as a predictor for patients’ extubation outcome. Study design : Prospective crossectional single centred observational study . Place and duration of the study : The study was carried out in PCCM department of Kgmu from January 2023 to October 2023. Methodology: Diaphragm excursion , diaphragm thickness at inspiration and expiration was measured using ultrasonography on right side at 8 th and 9th intercostal space between anterior and mid axillary lines. Quadriceps thickness was also measured at mid point between the anterior superior Iliac spine to patella and was compared with the outcome of the intubated patient . Results : Out of 42 patients 52% were male(n=22) and 48% were female (n=20). The study showed that the diaphragmatic excursion ( p value <0.001 ) and diaphragmatic thickness at inspiration (p value 0.007 ) was significant in predicting outcome of the patient from mechanical ventilator but quadriceps thickness had no significance( pvalue 0.012). The excursion of the patient <7 , 7-11 and >11 has extubation success of .0%, 46.2 % and 53.8 % respectively. The diaphragmatic inspiration thickness of <1.65 , 1.65 - 3.7 >3.7 has successfull weaning of 0% , 100% and 0% respectively. Conclusion: Diaphragm excursion plays strong role in predicting the success of extubation and preventing icu acquired weakness. The study reflect the role of diaphragmatic thickness in better outcomes. Quadriceps muscle couldn't be related much with weaning and extubation.