Brachial plexus is a complex bundle of nerves, extending from the neck to the axilla, which supplies both motor and sensory fibres to the upper extremity. So clear understanding of anatomy and distribution of nerves is effective for regional anaesthesia. The introduction of ultrasound guidance techniques not only reduces the possible risk of pneumothorax but also allows a faster onset time of the block, with a reduction of the volume of local anaesthetic mixture,that has to be injected for a successful peripheral nerve blocks Also detects vascular structures and pleura, needle tip control, and monitoring of distribution of local anaesthetic (LA). After obtaining the approval of institutional ethical committee of hospital, a retrospective review of anaesthesia register from January 2015 until January 2020 (60 months) was done. All the adult patients who underwent upper limb surgeries underwent peripheral nerve stimulator guided injections for supraclavicular brachial block and paediatric patients under axillary block by landmark technique from January 2015 to July 2017, will be allocated to PreUS group and after availability of portable ultrasonography as Post-US with ultrasonography being available since July 2017 and outcome will be recorded. As it is a retrospective study, all possible data will be included and analysed. As it is a retrospective study, nothing could be excluded.So comparision for 30 months of pre ultrasound and 30 months of post ultrasound period. Conclusions: In adults ultra sound increased 26 % rise in no of surgeries under regional anaesthesia which is quite significant.The reduction in mean effective volume(MEV) in adults was about 51% by the application of ultrasound. In children, there was a definitive rise of 60 % increase in no of cases under Axillary approach of brachial block and 43% reduction in the mean effective volume(MEV).