It is a historical fact that most Kenyan communities are haunted by actual or potential ethnic conflicts. Kenya comprises of many ethnic communities that are religiously shaped by their cherished cultures. These are the cultures which influenced the peoples’ behavior and conduct. It is therefore true that most Kenyan communities were directly or indirectly affected by inter-ethnic community crisis. Inter-ethnic conflicts that were so prevalent among the Kenyan communities concerned cultural issues though culture was not uniform in all communities. This study analyzes the contribution of culture in the frequent conflicts between the Maasai and Kuria communities from 1920 to 1963. Conflict theory was employed to examine the conflicts and was reinforced by structural functionalism theory in the analysis. The assumption in this study was that culture was specifically a contributory factor in regional conflicts and therefore needed a local examination. The study relied on secondary and primary data such as those from the existing written sources and from the affected peoples of Kuria and Trans-Mara region. Purposive sampling was used to reach out to the informants. The research was guided by the specific research questions and objectives which included establishing the influence of rites of passage, Moranism/Abamura and religious beliefs on cross-border conflict between the Maasaiand Kuria from 1920 to 1963. This research was confined to cultural issues between 1920 – 1963. Scarce data, hostile respondents, vast land, sparse population and poor means of transport were some of the limitations encountered. The targeted groups of people for interview included the District Commissioners, head teachers of primary and secondary schools, church leaders, chiefs, clan elders, Border Peace Committee members, traditional healers, Morans/Abamura, Agricultural officers and ordinary residents. This research is descriptive and was based at Kegonga Division of Kuria and Masurura Division of Trans-Mara. Data collected was analyzed and the validity of the research examined together with its reliability. The backgrounds of the Kuria and Maasai were also studied to examine the progressive development of cross-border conflict between them since 1920 to 1963 and how culture had been a hindrance to positive adoption of modern lifestyle. Data collected from the field of study was analyzed, discussed, presented and interpreted within the set objectives of the study. The study also examined the aspects of the cultures of both the Maasai and Kuria which were seen to perpetuate cross-border conflict. Such cultural aspects include circumcision, marriage, Moranism/Abamura and traditional religion. Lastly, the summary of the findings, recommendations, suggestions for further research and contribution to literature are presented. The findings of the study revealed that the rites of passage, Moranism/Abamura and religious beliefs contributed to cross-border conflicts between the Maasai and Kuria.