Performance of building projects is affected by several factors and project management practices stand out as one of them. Different organizations carry out different project management practices. Considerably, there is difference between the time performance of different projects managed by different organizations. Cost performance tend to differ significantly from project to project. Quality performance of a given project tend to remain unchanged irrespective of the project management organization in charge. Notwithstanding, significant difference exists between the overall project performance when practices differ from organization to organization. Likewise, project performance remains significantly unchanged when the corresponding project management practices do not differ from one project management organization to the other.