The aim of this investigation was to study the effects of two different cultivars of sweet corn (Zea mays var. rugusa, L.), three different plant spacings and three different mineral NPK fertilizers levels, and their interactions on vegetative growth, yield and yield components, and kernels quality characters. To achieve this aim, two field experiments were conducted at the Agricultural Research Experiment Station, King Abdulaziz University, Hada-Alsham,Saudi Arabia, during 2006 and 2007 summer seasons. The obtained results indicated generally that the differences among the means values of each studied factor, first-and second - order interactions for the vegetative growth, yield and its components, and kernels quality characters, were significant; but, with different magnitudes, during the two summer seasons. Also, the results indicated generally that the cultivar "Merit" was the best for the most studied vegetative growth, and yield and its components characters, whereas, the cultivar "Challenger" was the favourable cultivar for the kernel quality parameters. The results indicated that increasing either plant spacings or the mineral NPK fertilizers was associated with corresponding increments in most of the studied characters of sweet corn, during both summer seasons. Generally, the results of the first-and the second-order interactions effects on all the studied characters, showed that one of the used cultivars with either widest spacing between plants or/ and the highest level of mineral NPK fertilizers gave the highest means values of all the studied characters, during both growing seasons.