A hydraulic free piston engine (HFPE) combines a diesel engine and a hydraulic pump into one compact component. In practical view there is only one linearly moving part in the HFPE, the piston assembly containing three parts, combustion and hydraulic pistons and piston rod. The piston assembly moves during operation linearly back and forth between left and right extremes by means of the fuel energy. Simultaneously hydraulic piston produces directly hydraulic energy. The HFPE enables higher power density and lower manufacturing costs than a conventional engine-pump combination. These are consequence of simpler design.This paper presents experimental results of Dual Hydraulic Free Piston Engine. The presented results contain measured data from a running engine and analysis based on the results of the operation. The handled results include piston motion, pumping and combustion processes. Shown results are unique, because such results have not been presented before.The measurement showed that the dual hydraulic free piston engine is working in practice. The performance of the prototype does not reach the required values but still the engine performance in the initial test was satisfying.