Personality development play an important role in the life of every individual. Poor personality development has made some students become progressively inadequate and alienated from the activities of the school. Conscientiousness is a multi-dimensional trait of personality that includes dimensions such as self-efficacy, self-discipline, and goal orientation. In view of the discussion, the researcher examined conscientiousness indices as predictors of special needs pupils’ academic performance in inclusive basic schools in Lagos Metropolis. The respondents comprised 210 pupils with special needs selected from 10 inclusive basic schools in Lagos Metropolis. Questionnaire was used to gather data for the study. The questionnaire was validated by experts and reliability of the questionnaire was also carried out by administering it to 20 pupils with special needs who were not part of the sample. The data collected was analyzed using both descriptive and inferential statistics. The demographic information of respondents was described using frequency and percentages. Research question 1 and 2 were answered using mean rating, while the formulated hypothesis was tested using Multiple Regression statistics. The formulated hypothesis was tested at 0.05 level of significance. The result of the study showed that significant relationship among conscientiousness indices (self-efficacy, goal orientation and self-discipline) and academic performance of pupils with special needs in inclusive schools in Lagos Metropolis. It was then recommended that, school management should assist the pupils in such a way that they will have strong belief in their ability to excel and set achievement goals in life.