In order to evaluate the effect of tillage systems on yield and yield components of wheat (Triticum aestivum L.) under different nitrogen fertilizer levels, experiment was conducted as a split plot based on randomized complete block design with three replications at Agricultural Research Station of (Sistan Dam), Zabol University, Iran, in 2014. Tillage systems were included: no tillage, minimum and conventional tillage as a main plot and nitrogen levels were included: 0, 100, 160 and 220 kg ha^-1 as a sub-plot. Results showed that the highest seed yield was obtained from conventional tillage system and there were no significant differences between no-tillage and minimum tillage systems. The maximum plant height, leaf area index (LAI), number of fertile tiller per plant, number of seed per spike, 1000-seed weight, biologic yield, harvest index and seed protein content were belonged to the conventional tillage system. Increasing nitrogen levels to 220 kg ha^-1 enhanced plant height, LAI, number of fertile tiller per plant, number of seed per spike, 1000-seed weight, seed and biologic yield, harvest index and seed protein content significantly. Interaction of tillage systems×nitrogen on the number of fertile tiller per plant and LAI were significant. The highest number of fertile tiller per plant and LAI were obtained from conventional tillage and 220 kg ha^-1. The results indicated that the conventional tillage along with the high level of nitrogen is more suitable for the studied region.