Quantum teleportation is a fundamental protocol in quantum communication. Errors (contamination) during the preparation of quantum states can affect the teleportation performance. This paper analyzes in detail the impact on the standard quantum teleportation protocol when the initially shared entangled state is prepared as |Ω⟩ = α|00⟩ + β|11⟩, rather than an ideal Bell state. Through mathematical derivation, we demonstrate how, under such a contaminated state, the correspondence between Alice’s Bell measurement outcomes and Bob’s corrective operations changes. Furthermore, we extend the analysis to three-dimensional (qutrit) systems to examine how high-dimensional contaminated states affect the teleportation process.