Abstract Slug frequency, the number of liquid slugs passing through a point per unit of time, is an intrinsic parameter that is used to characterize multiphase slug flows in pipes. In this review we discuss practical aspects of slug frequency for industrial purposes from an examination of published literature and available experimental data. The review shows that slug frequency appears to play a key role in the modelling of intermittent flow using 1‐D mechanistic slug models and 3‐D computational fluid dynamics tools. In addition, various global parameters and phenomena used to design, optimize, and control industrial pipelines are directly impacted by slug frequency. This manuscript highlights the importance of slug frequency not only for petroleum engineering but also for chemical, nuclear, and mechanical engineering.