Abstract This paper presents the results of a preliminary investigation utilising an inertial measurement unit (IMU) within horizontal slug flow pneumatic conveying. Challenges of using an IMU within pneumatic conveying were discussed, in particular the importance of sensor fusion. Different sensor fusion algorithms were considered and Madgwick's filter was selected as most appropriate. Two IMUs were simultaneously inserted into the pipeline allowing the particle velocity to be measured as the sensors mimicked the motion of the slug particles. Furthermore, barometers on the IMUs allowed for in-situ pressure to be measured as the particles travelled through the slug. Benefits and drawbacks of the use of IMUs, particularly in relation to slug flow pneumatic conveying, were discussed and results of a preliminary investigation conveying plastic pellets in a horizontal pipe were presented. By analysing the pressure outputs of the two IMUs it was shown that the pressure profile over the slug is not linear. Lastly, by examining the pressure and velocity trends, it could be seen that there is an inverse relationship between pressure and velocity. Moreover, it was discovered that there exists a time delay where velocity changes occur first, followed by a delayed change in pressure.