The objective of this study was to investigate the internal structure of the Performance Index in order to establish the interrelationships between the eight unit performance latent variables. The present study forms part of a larger study aimed at validating the Leadership Behaviour Inventory (LBI) (Spangenberg & Theron, 2002b) against work unit performance. The validation sample, after imputation of missing values, consisted of 273 cases with observations on all 56 items. Item analysis and dimensionality analysis was performed on each of the sub-scales using SPSS-windows. Thereafter, confirmatory factor analysis was performed on the reduced data set using LISREL. The results indicated satisfactory factor loadings on the measurement model. Acceptable model fit was achieved. Subsequently, the structural model was tested using LISREL. The results provided statistics of good fit. Only four hypotheses failed to be corroborated in this study. The results are discussed and suggestions for further research are made. Opsomming Die doel van hierdie studie was om die interne struktuur van die Performance Indexs (PI) (Spangenberg en Theron, 2002b) te ondersoek ten einde die interverwantskappe tussen die agt latente eeheidprestasiedimensies te bepaal. Hierdie studie vorm deel van ’n meer omvattende studie wat daarop gemik is om die Leadership Behaviour Inventory (LBI) teen werkeenheidprestasie te valideer. Die steekproef, na imputasie van ontbrekende waardes, het uit 273 gevalle bestaan met waarnemings ten opsigte van al 56 items. Item- en dimensionaliteitontledings is met behulp van SPSS-windows op elke subskaal gedoen. Bevestigende faktorontleding is daarna met behulp van LISREL op die verkleinde datastel uitgevoer. Die resultate het op bevredigende faktorbeladings vir die metingsmodel en ’n bevredigende passing van die metingsmodel gedui. Daarna is die strukturele model met behulp van LISREL getoets. Die resultate het bevredigende passing getoon, met slegs vier hipoteses wat nie deur die studie bevestig is nie. Die resultate word bespreek en voorstelle vir verdere navorsing word gemaak.