Guerrilla fight in the twentieth century was considered as an important strategy for some political groups and organizations across different countries like China, Cuba, Algeria, Brazil, and Iran. Guerrilla fight is directly linked to a geographical place. Therefore, cities and villages are regarded as the main places for the operation of partisan battles. In Iran, some groups adopting an armed policy and guerrilla strategy embarked on combatting the Pahlavi Regime, among which the Organization of Iranian People’s Fedai Guerrillas (OIPFG) can be considered as the initiator of this action in practice. The present research aimed to identify the factors making Iranian People’s Fedia Guerrilas choose cities as their places of priority for the guerrilla warfare and the results of their performance in their urban guerrilla warfare against Pahlavi Regime. The findings of this study using a descriptive-analytical approach and based on documents and library texts show that the following four major factors made the OIPFG centralize its activities in the urban areas: the failure in Siah’kal operation, physical-spatial features of cities, the centrality of the Pooyan-Ahmadzadeh group in the OIPFG, and the emulation of successful patterns of urban guerrilla warfare in other countries. Furthermore, the performance of the OIPFG shows that after their failure in Siah’kal and the transfer of their activities to the cities, guerrilla battles gained more success in four ways of assaults, sabotage, revolutionary executions and armed propaganda.