ABSTRACT: In this paper the diesel engine cylinder pressure is reconstruction in the crank angle domain using the measured engine vibration and acoustic emission. This technique depends on frequency analysis of engine vibration and acoustics. The frequency response functions (FRF′S) are determined from the measured cylinder pressure, engine vibration and acoustic emission at specified engine speed and loads. The cylinder pressure is reconstructed from the measured engine vibration and acoustics at similar conditions by applying the inverse filtering technique using the already determined FRF′S. The measured and the reconstructed cylinder pressures are compared to each other for vibration and acoustics at different loads. Comparison between the reconstructed cylinder pressure from acoustics and vibration signals at the similar speeds and loads with the measured ones show good results as they are predicated. Slight differences in results for measured and reconstructed cylinder pressure for both vibration and acoustics is due to non-linearity of the engine system. The measured and reconstructed cylinder pressures from vibration signal are compared to that ones from acoustics for similar conditions and they have the same results.