The application of organic wastes combined with or without mineral fertilizer to soil is considered as a good management practices in any agricultural production system because it improves, plant quality and soil fertility. The objective of the present study is to evaluate the effect of three compost types (plant residues, animal residues and mixed) when mixed with mineral nitrogen fertilizers, on cucumber (Cucumis Sativa) plants and soil properties. A field experiment was carried out at El-Nataf farm, Sakha, Agricultural Research Station, Kafr El- Sheikh Governorate, Egypt during the two successive summer seasons of 2007 and 2008. The results showed that the mature compost of plant residues was higher in saturation percent and lower in C/N ratio, pH, electrical conductivity and bulk density than the animal and mixed composts. The study demonstrated that the average cumulative cucumber yield was higher with 75% mineral N + 25% organic N treatments compared to other treatments throughout the experiment, especially in the plots treated with plant compost during the two successive summer seasons of 2007 and 2008. The average nitrate of petioles in the plots treated with N 100% organic decreased by 52-69 % compared to 100% mineral N. The average nitrate content of cucumber fruits was only detected in the plots treated with 100% organic N from the composts tested. The nitrogen and phosphorus content of the soil significantly increased, as did the soil organic matter, with the increase of organic nitrogen applied. The experimental results confirmed that the combination of organic and inorganic fertilizers could increase plant growth, yield, quality and soil fertility. It also confirmed that composted organic wastes can be used to substitute for around 25% of chemical nitrogen fertilizers.