Due to the need for faster and more automated work, modern construction is increasingly developing, and more and more areas are affected by the new possibility of concrete installation using 3D printing. 3D printing technology requires strict criteria for fresh and hardened properties, which condition both the selection of components and mix design for 3D printing concrete. The development of concrete for 3D printing was mostly influenced by the achievements in the area of self-compacting concrete and wet process of the performance of jet concrete. The greatest changes this technology brings are the installation of concrete without formwork and without vibration of built-in concrete. The prepared concrete mix is transported through the pipe system under pump pressure to the printer head nozzle through which thin continuous concrete fibres are extruded, forming together concrete layers, forming the entire concrete element. Due to its specificity, this technology brings some new characteristic and methods of testing them. Properties that the mix of fresh concrete for 3D printing must meet the ability to transport through the pipe system and to be extruded through the nozzle, buildability of a large number of layers without significant deformations, and sufficient open time for printing process with good workability. An optimum mix of concrete satisfying the before mentioned fresh properties, good quality performance and proper curing method should provide also hardened properties, which are high compressive and flexural strength, tensile strength in terms of firm and high quality bond between the layers and minimisation of drying shrinkage which is critical feature of concrete for 3D printing, since concrete is hardened without framework. Numerous research by scientists in the field of construction over the past decades has brought important guidelines for the design of concrete for 3D printing. It has been established that to achieve the required properties, a maximum grain of the 2 mm river aggregate is required, a replacement of a part of cement with mineral additives such as fly ash to improve workability and silica fume to increase the yield stress without affecting viscosity, the dosage of superplasticiser for minimazing water-binder ratio and to achieve sufficient workability, and the dosage of retarder to achieve flowability throughout the printing process, the use of fibres to increase flexural and tensile strength, and accelerator to control setting of concrete by the nozzle. The optimum mixture must meet the strict compressive strength criteria of 100 MPa and flexural strength of 12 MPa at 28 days. This paper describes the course of mix design, the methods for testing relevant properties and the achieved properties for concrete installed with 3D printing technology.