Summary In an attempt to reduce the high intake of dietary salt, the processed meat industry is continuously looking for alternative solutions for salt replacement. The objective of this study was to investigate the effect of employing sonication on the diffusion of sodium salt (NaCl) and a salt replacer (SR) into pork meat. Ultrasound‐assisted brining experiments were carried out using 5% NaCl or SR at power levels of 9.0 and 54.9 W cm−2 for 120 min. Samples were assessed for cooking loss, water mobility, deformation, while thermal behaviour was analysed using differential scanning calorimetry (DSC). Experimental data obtained were used to estimate the mass transfer coefficient of the brining process. The mass transfer equation was solved using the Runge–Kutta method. Results showed that the ultrasonic treatment had a low influence on the mass transfer of salt into pork samples. Only at high ultrasonic power was the mass transfer coefficient higher than the static brining. This study has improved our understanding of the effect of sonication on diffusion of NaCl and SR in pork meat and will enable a more systemic approach to future healthy meat product development.