Status of electroweak tests with heavy quarks

The measurements of the partial decay-widths and forward-backward asymmetries for $\rm{Z} \rightarrow \bb$ and $\rm{Z} \rightarrow \cc$ test the Z couplings to the initial state $\ee$ pair and th e heavy quarks in the final state. The four LEP detectors have registered about four million hadronic Z decays each and SLD at SLC has recorded 300000 Z decays with highly polarised electron be ams. The high statistics as well as the good tracking, vertexing and particle identification capabilities of the detectors allow high precision measurements of these quantities. The measurements of the electroweak observables with heavy quarks are reviewed. The results of the different analyses are combined and interpreted within the framework of the Standard Model of electroweak interactio ns. In all cases good agreement with the Standard Model predictions is found, severely limiting the room for modifications of these quantities from new physics.