At places far from the energy grid lines, freshwater is sometimes needed. Consequently, even countries with rich energy resources, such as the Arabian Gulf countries, have shown strong interest in desalination processes that often use renewable energy sources.  In the present work, a desalination unit depending on the humidification-dehumidification principles is fabricated and tested under Baghdad, Iraq conditions. The HDH system under study consists of 6 parabolic trough solar collectors (PTSC) of a total aperture area of 8.772 m², the humidifier, and the dehumidifier and a tracking system. The effects of salty water flow rate and the HDH air-water configuration cycles on the system performance are investigated. The results revealed that the maximum freshwater productivity is about 6.37 lit/day during the testing period (6 hours per day extended from 9 am to 15 hr); the average daily productivity is 1.062 lit/hr when the salty water flow rate is 1lit/min. Increasing salty water flow rate above 1 lit/min deteriorates the productivity of freshwater. The best configuration of the air-water cycle is the closed air open water circuit.