In the process industry the use of static mixers is constantly rising. Notwithstanding, due to the multitude of available types, the selection of a proper construction is not as simple and requires the knowledge of complete description of a device. In the performed research there was an attempt to present the complete fluid-dynamic characteristics of two static mixers: Kenics, well known and commonly used, and Koflo, which has not yet been described in the relevant literature. The empty pipe was also studied as a background for comparison. However, according to the huge amount of gathered data, the report was divided into separate parts, dedicated to pressure drops, residence time distributions, and mixture homogeneity, respectively. The presented paper is focused on the pressure drop analysis which contains the experimental study, the validation of the obtained data on the basis of manufacturer's correlations, as well as computational values and the presentation of new pressure drop relations that enable the pressure drop predictions from Eu or Ne number. As a result of the accomplished study, a good accuracy between the values calculated form given equations and those achieved in the experimental manner was confirmed. It was also shown that due to smaller energy consumption Koflo static mixer can be successfully used instead of Kenics. What is more, the presented report clearly states that static mixers require a huge power demand which leads to the increased maintenance costs and that information should be considered during the system design.