Literature revealed that the patterns/methods of scoring essay tests had been criticized for not being reliable and this unreliability is more likely to be more in internal examinations than in the external examinations. The purpose of this study is to find out the effects of analytical and holistic scoring patterns on scorer reliability in biology essay tests in Enugu Education Zone of Enugu State. Post-test only control group design was used. All the 212 Biology teachers from the thirty one secondary schools in Enugu Education Zone of Enugu State were used. The researcher constructed Biology essay test (BET) with scoring guide on biology essay tests (SGBET) for data collection. The research question was answered using Pearson's Product moment correlation coefficient (r). The hypothesis was tested using t-test. The results showed that the use of the holistic scoring pattern was found to be the most reliable followed by analytical scoring pattern. Recommendations were made based on the findings of the study.