New grinding technology has been developed for crankshaft bearings in shipboard diesel engines. This novel technology offers improved performance of the technological processes and saves considerable time in repairing ship diesel engines. However, the impact of this novel grinding technology on the surface roughness parameters is not yet clear and requires additional scientific analysis. Furthermore, it is important to note that crankshaft bearing surfaces must be seen as three-dimensional objects, and their microtopographical surface roughness parameters have to be defined so as to reflect the actual surface. The three-dimensional parameters of the crankshaft bearing surfaces were defined during PhD research. The mathematical model of these microtopographical roughness parameters was determined. Also, the surface roughness parameters were calculated based on the actual metrological and technological surface parameters of the crankshaft bearings. It was stated that the optimal three-dimensional surface roughness parameters for crankshafts are the following: mean arithmetical deviation of surface RaT, and two perpendicular surface spacing parameters between the peaks Sm1 and Sm2. Thus the three-dimensional surface roughness parameters of shipboard diesel engines crankshafts were identified.