Conflicts are unavoidable in many circumstances and generally they include relational disputes between two or more parties such as land conflict between farmers and pastoralists as stipulated in this study. The study was conducted in Kiteto district, Manyara, Tanzania. The objective of the study was to find out unresolved major causes of land conflict in Kiteto district, Manyara, Tanzania. The study followed a positivism research philosophy whereby descriptive research design was used as well as quantitative research approach. Means and standard deviations were used to analyze data on unresolved major causes of land conflict in Kiteto district, Manyara, Tanzania. Findings revealed nine unresolved major causes of land conflict in Tanzania which were; competition over resources like land and water, land policy deficiencies and contradictions, imbalance political representation in leadership, bad governance and corruption, human rights violations, pastoralists? grazing cattle in farmers? farms, no proper demarcation of land use plan, increased human and livestock population scored and insecurity of land tenure. The study concludes that resolving unresolved major causes of land conflict in Tanzania is key to peaceful and harmonious relationships between communities in Tanzania especially those conflicting over land use.