The objective of this study was to evaluate a new method of leaky subsurface irrigation for olive tree and comparing its effects on olive tree growth and olive yield components with surface irrigation under water and wastewater application. This study was conducted at Isfahan University of Technology (IUT) in 2010 and 2011. The field experiment included two irrigation systems, (leaky subsurface irrigation (LSI) as new method of irrigation and surface irrigation (SI)) and two water qualities, (agricultural water and wastewater) that consisted of young (2 years) and mature (8 years) olive trees. The experimental treatments were arranged in split-plot design in a randomized complete block with three replicates for young and mature olive trees, separately. Also, some hydraulic performances of the LSI system such as variation of water level, infiltration rate and wetting front were considered under three discharge rates (0.1, 0.2, and 0.3 l/sec) and three water application volumes (30, 60, and 90 liters) under a silty clay soil in another site at IUT. The irrigation amount and the irrigation efficiency were similar for LSI and SI systems. The olive tree growth characteristics such as tree height, shoot growth, and canopy width/volume were measured during two years and for olive yield which was measured at harvest time in 2011. The fresh weight, diameter, length and the volume of olive fruit were affected (p 0.05) by irrigation systems. Also, the fresh weight, water content, diameter and the volume of fruit were affected (p 0.05) by interaction of irrigation system and water quality. However, there was no significant effect of water quality on dry weight, fresh weight, diameter, length, water content and volume of olive fruit. All fruit characteristics were higher for LSI system as compared to surface irrigation system and were higher for wastewater as compared to agricultural water. The results showed that the tree height in 2010 and 2011, and the canopy volumes in 2011 were affected (p 0.05) by irrigation system, and tree height was affected (p 0.05) by water quality in 2011. The tree height, shoot growth, the width and volume of canopy were higher in LSI system as compared to surface irrigation for young and mature olive trees. The maximum dry weight of fruit (1.79 gr) and fresh weight of fruit (4.30 gr) were obtained under LSI system on applied wastewater while the lowest dry weight (1.42 gr) and fresh weight (2.98 gr) were obtained when applied agricultural water under surface irrigation. It was considered that two phases and four stages had different trends for discharge rate and infiltration rate under LSI system. The increase in the volume and discharge of applied water at the feeding phase caused an increase in water level in pipe. By increasing the volume of applied water in a constant discharge, intake rate increased in the feeding phase and decreases in the recessive phase. By increasing discharge, the intake rate in constant volume for applied water increases in the feeding and recessive phase. For constant volume of water application, an increase in discharge rate caused an increase in depth of wetting front, and a decrease in the discharge rate caused an increase in width of wetting front. The results showed that the wetting patterns depended to discharge rate and applied water volume. Overall, the results showed that leaky subsurface irrigation system is a suitable method to use wastewater for mature olive trees. Further research will be conducted for urban landscape trees to find benefits and limitations of LSI system in the urban landscape. Key words : Leaky-Subsurface irrigation system, wastewater, olive, intake rate, wetting front, urban landscape