In low-permeability formations such as tight gas reservoirs, a well would be economic only if an effective hydraulic fracturing technique is selected. In central part of Sultanate of Oman a deep tight gas field is developed with hydraulic fracture stimulation. Normally, between 7 and 13 frac stages are done per well. Majority of wells are vertical with pay zones separated with shale layers that prevent fracture growth. Plug & perf is a common technique used in this field, therefore there are multiple well interventions during Hydraulic Fracture operations that consume time and delay the well delivery. By deploying multistage frac completion with the objective of producing, enhancing and cost/time savings, the effectiveness of the fracturing operations was expected to increase. Equipment selection, design and development was performed based on well conditions, casing design, operational parameters and production gas composition. Multistage frac completion allows the frac operation to be continuously performed without the need to conduct intervention activities such as running/setting frac plugs, perforating, milling and clean-out between intervals. The intervention activities can be conducted at the end of the frac operation in single-trip deployment if desired. The success in North America in horizontal tight gas wells has opened a door for implementation of this system in vertical wells in Sultanate of Oman. The main challenge in deployment of this system in vertical wells is the accurate positioning of the sleeves. The shale layers between the pay zones could be as narrow as 5 m or less and a small pay zone might be easily missed. Besides, deployment and cementing operations are equally essential as proper zonal isolation is a must with water zones embedded in between. This paper is discussing the lessons learned from utilization of multistage frac completion in vertical deep wells (around 5000 m) covering the completion and Hydraulic fracturing stimulation operations. This technique has proven significant cost & time reduction and production increase as well as reduced HSE exposure contributing to better gas recovery, improvement in operator's performance and energy delivery to the country.