The current experiment has been conducted to study the effect of foliar application of seaweed extract (AIGA CIFO 3000) at three concentrations; 0, 1.5 or 6mg. L-1 and NPK fertilizer at three concentrations also; 0, 1.5 or 3 g. L-1 and their combination on some growth parameters and yield of cucumber Cucumis sativus L. cv. Selion. The experiment was carried out in a plastic house at the College of Agriculture University of Al-Qadisiya during the period from 28-12-2013 to 22-4-2014. Radomized complete block design has been used with three replications. The spray with seaweed and NPK fertilizer is done twice; the first one is after one month of planting in the permanent place, and the second one is after two weeks from the first spray. Plant height, number of branches, leaf chlorophyll content are have been measured. Also, early and total yield and fruit characters such as length, weight, and fruit diameter, total soluble solids and vitamin C are calculated. The results show that plant height and number of branches are increased significantly with seaweed and NPK treatments, especially at the higher concentrations. Also, chlorophyll content in leaves is also increased significantly at the higher concentration of the seaweed. The early yield is increased at both concentrations of both factors used, while there is a significant increase in total yield at the higher concentration of both factors in compare to control. The two concentrations of seaweed extract cause significant increase in fruit weight, while the treatments have variable effects with regard to fruit length and diameter. There was a gradual increase in TSS and vitamin C with the increase of the concentrations of both seaweed extract and NPK fertilizer.