Two successive winter field experiments were performed at 2015/2016 and 2016/2017 seasons at Vegetables Research Station, Faculty of Agric., Mansoura Univ., Egypt to study the effect of different fertilization treatments in terms of NPK fertilizer ratios and rates on growth, yield and quality of cauliflower (cv. Fargo) cultivated under silty clay loam soil conditions by furrow irrigation system. Four NPK fertilizer ratios (1.0:1.0:1.0; 1.0:1.0:0.5; 1.0:0.5:1.0 and1.0:0.5:0.5) with three fertilizer rates (50, 100 and 150 kg fed^-1) as a soil application were tested. Each experiment comprised of 12 treatments and were designed as split plots and replicated three times in a randomized complete blocks design. The obtained data of this investigation clearly demonstrated that, all studied parameters such as vegetative growth characters (i.e., plant height and leaves number, plant leaf area, leaves fresh weight and leaves dry matter percentage), leaves chemical composition (viz. N, P, K, chlorophyll a, chlorophyll b and carotenoids contents), Curds yield and its components (i.e. curd weight, curd diameter, curds yield/fed. and curds dry matter percentage) and curds chemical quality attributes (namely, Vitamin C, TSS, N, P and K contents) had significantly been influenced with NPK fertilizer ratios, rates and their interactions in both seasons. Concerning the effect of NPK fertilizer ratios, 1.0:0.5:1.0 ration gave the highest values for all forecited characters, whereas 1.0:1.0:0.5 ratio recorded the lowest values in this respect. Regarding the impact of NPK fertilizer rates, the rate of 150 kg fed^-1 achieved the maximum records for all mentioned parameters compared with other two fertilizer rates. Respecting the influence of interaction treatments, both commercial inorganic NPK fertilization treatments resulted from whether fertilizer ratio of 1.0:0.5:1.0 or 1.0:1.0:1.0 combined with 150 kg fed^-1 fertilization rate recorded the best means for all aforementioned studied traits as compared with other all NPK fertilization treatments in this regard. Hence, it could be recommended that fertilization of cauliflower crop (cv. Fargo) with commercial inorganic NPK fertilizers blend resulted from combination of NPK fertilizer ratio 1.0:0.5:1.0 with the fertilization rate of 150
kg fed^-1 in order to obtain high parameters of vegetative growth, yield and quality under similar research conditions.