Geo-textiles are an important part of geo-synthetics group of materials. Geo-textiles are extensively utilized in civil engineering projects. Geo-textiles fulfill various functions required by civil engineering criteria due to their varied properties. Hydraulic Properties of geo-textiles is of paramount importance in civil engineering projects. In this research cross-plan permeability of nonwoven needled geo-textile fabrics was investigated. Samples of geo-textile materials were made using commercially melt spun polypropylene fibers. An apparatus capable of measuring cross-plan permeability under zero normal-stress confinement was made according to ASTM D4491 standard. The samples of geo-textile materials were produced using two-stage needle punching process in which production parameters such as mass per unit area, punch density and thickness were varied. Hydraulic experiments were conducted according to both constant and falling head test methods under linear flow condition. Cross-plan permeability is characterized by the coefficient of permeability according to Darcy´s law. Permeability of the experimental geo-textile samples were compared to the permeability of conventional granular civil engineering materials. Based on the results it was concluded that such thin and light geo-textiles can successfully replaced thick and heavy conventional granular materials. The effect of factors such as fabric thickness, the amount of punch density, fabric porosity and weight on cross-plan permeability of nonwoven needled geo-textile fabrics together with relationship between minor losses coefficient and friction factor with Reynolds number were studied. The experimental samples of geo-textiles were produced at constant needle penetration of 13 mm. It was found that reduction of punch density imparted to geo-textiles caused the fabric thickness to be increased. The effect of geo-textile thickness on fabric permeability in relation to punch-density was also investigated. It was concluded that increases in geo-textiles thickness, correspondingly increases the fabric opening size. This in turn enhances the fabric permeability. Punch-density also affects fabric permeability. Results showed that fabric permeability is reduced when the amount of punch-density is increased. This may be due to the existence of an inverse relation between punch density and fabric porosity. It was found that degree of compactness of fabric increases with increases in the amount of punch-density. The increase in fabric compactness results in reduction of the porosity of the fabric, thus the observed reduction in the permeability of the samples. . The results showed that permeability rate decreases as weight per unit area of geo-textile is increased. The increase in the weight per unit area of geo-textile is due to the increase in the number of fibers present the fabric structure. This leads to increases in the flow path length and resistance. These are in accordance to the modified Kozeny equation which confirms the reduction of permeability of fabric. Representation of experimental data on log-log paper showed a negative linear relationship between friction factor and Reynolds number. Graphical relationship between minor losses coefficient and Reynolds number was also provided. This plot showed that, geo-textiles sample with higher permeability exhibit smaller minor losses. Comparison of results obtained in this research with the previous studies in relation to the effect of factors such as thickness, porosity, weight per unit area and punch density on the permeability, showed acceptable agreement.