Fire has always been a serious threat to buildings. The September 11 incident at the World Trade Center in 2001 has encouraged significant interest in understanding the behavior of structures under fire. The reduced material strength and additional thermal stresses due to elevated temperature are leading to the failure of the member. This study is an attempt to understand the effect of continuity in steel frames under different levels of elevated temperature. A 3-story steel building with a footprint of 25 m x 22.5 m is modeled using SAP2000 using a non-linear static analysis. Three models were used with different spans length in the load-bearing direction to study the effect of the continuity aspect on the behavior of the structure under elevated temperatures. Spans in the first model were equally spaced by 7.5 m for each span, and in the second model, the middle span was shorter than the equaled edge spans, where the middle span was 4.5 m and edge spans were 9 m, and finally, the middle span was longer in the third model with a middle span of 9 m and edge spans of 6,75 m. Each model was studied for three temperatures which are 250, 500, 750 °C. Thermal loading was applied considering three scenarios based on the location of application: Outer span, inner span, and the whole span. In addition, results were compared for fixed base and pinned base conditions. The results showed that as the temperature increased, the internal forces and deformation on the affected beams (Moments at spans and supports, axial forces, and deflections) increased. Furthermore, the bending moments in both spans and supports as well as the axial forces in spans are affected by the location of the thermal loading. It was observed that the members, which are near the location of thermal loading, experienced higher internal forces. Generally, results illustrated that with the pinned base condition, bending moments at both supports and spans are more than the values with the fixed base condition, which is happening due to the contribution of the fixed support to carry moments. The maximum axial force was more in magnitude with fixed support than with pinned support, this is because the pinned base will allow for expansion of the beam and release part of the axial force. On the other hand, the axial force transferred to the next span is more when it is pinned at the base which is again due to the flexibility that pinned support provides. There was no significance of changing the base support on the plastic hinge formation mechanism, as the hinges developed approximately at the same levels of temperatures and showed the same overall behavior. Additionally, number of plastic hinges were increased as the temperature increased because as the temperature increases the loading on members will increase and hence the member will undergo plastic behavior at different locations. However, in the cases of heating the outer or inner spans, only heated spans had plastic hinges formed, whereas in the case of heating the whole spans, there were hinges developed at the three spans.