Lateral loads are critical in the design of medium and high-rise buildings. In some cases these mat govern the design of several primary structural elements. The two principal types of lateral loads that act on building are: wind and seismic loads. Seismic loads depend on mass, seismic intensity and type of soil under the building. Heavy buildings are subjected to large seismic forces that vary along the building height. On the other hand, wind loads depend upon the terrain and the surrounding environment as well as geometry of the building. Both loads are independent but are related in particular circumstances. Previously, in most of the cases the seismicity and wind effects have been ignored in Oman because there was no design standard for earthquake and wind loading. However, Omani seismic code and wind data are available today. This research investigates the effect of seismic and wind loads on medium and high-rise buildings located in Muscat region. Different structural layouts and building heights were studied. The influence of shear walls on the behavior of building was investigated under wind and seismic conditions. Omani seismic code (OSC) was used to calculate the base shear and story shear distribution due to seismic load by Equivalent Static Load (ESL) Method. Wind pressure and its distribution was adopted in accordance with Euro-code EN1991 by considering parameters applicable to Muscat region. STAAD Pro was used to model and analyze the building. As far as seismic effect is concerned, Muscat is located in zone-I with a soil class of 'C'. However, as far as wind effect is concerned, Muscat has a basic wind speed map of 30m/s and terrain category-III. In this research, three different parameters were used such as aspect ratio (25 m x 25 m and 20 m x 40 m), height (11-storey, 15-storey, and 19-storey), and shear wall location (bare frame, core shear wall, and corner shear wall). All these parameters were compared in terms of three factors; lateral displacement, base shear and overturning moment. For the scenario of aspect ratio, it was demonstrated that 20mx40m-Z direction creates maximum lateral displacement under seismic load. However, 20mx40m-X direction has more effect on base shear and overturning moment under seismic effect as well. For the scenario of height, the 19-storey building achieved the highest lateral displacement value due to seismic load. For the scenario of shear wall location, it was found that corner shear wall has the least lateral displacement. It also provides the least vertical moments through all heights due to seismic. Therefore, it can be concluded that seismic load is governing all parameters and buildings located in Muscat should be designed primarily to resist earthquake loading.