The friction, wear and acoustic emission behaviour of various combinations of alumina, silicon nitride, and SAE52100 steel, operating under dry sliding conditions, was investigated. A designed ball-on-flat-disc type of tribometer was used to conduct these experiments. This apparatus, equipped with a force sensor, using silicon strain gauges, measured simultaneously the normal load and friction force. Both forces were used to determine the real-time value of the dynamic coefficient of friction. The AE signal arising from the interaction of the surfaces in dynamic contact was also detected and a data acquisition system was used to gather this signal as well as the outputs from the force sensor, at high frequency. The effects of test duration, sliding speed and normal load on the above mentioned tribological parameters were evaluated. The interest of this study further extended to assess the correlations that may exist between the integrated rms acoustic signal (AE) and the friction mechanisms, wear volume, friction work as well as the material removal power. Under the specific conditions of the present experiments, no consistent relation was found between the variations of AE and corresponding dynamic coefficient of friction (COF) as function of time. The variation of COF and wear rate, obtained considering a fixed total sliding distance of 500 m, as function of a range of sliding speed (0.05-2.5 m/s) and normal load (5-40 N) are presented. It was found that the test duration has an important impact on wear results of the experiments conducted at different sliding speeds and fixed travelling distance. More expected behaviour was observed when the relationships between the AE and wear volume, friction work, and material removal power were investigated considering the data obtained at different loadings and fixed sliding speed. Some models representing interesting relationships which could be used for predicting tribological properties in the case of practical applications, similar to the tribo-systems investigated in this study, are proposed.