Zinc is the most important micronutrient that limits crop production. Sorghum is highly susceptible to zinc deficiency. A green-house experiment was carried out at North-West University Research Farm to assess the effect of zinc fertilizer rates on the performance of different grain sorghum cultivars. The experiment was set as a 4 x 3 factorial fitted in a randomized complete block design.  The treatment factors comprised three zinc rates (0, 5.6 and 10.6 kg Zn/ha) and four grain sorghum cultivars (Avenger, Enforcer, NS5511 and PAN 8816). The measured parameters were plant height, number of leaves, chlorophyll content index, stem dry matter, leaf area, total dry matter, and panicle mass.  The sorghum fertilized with 5.6 kg Zn kg/ha had the highest chlorophyll content (69.90) at 77 days after planting. The highest chlorophyll content (70.90) was recorded with the Enforcer cultivar. The longest flowering days ( 83.93 days) was recorded with the application of  10.6 Zn kg/ha.  The application of 10.6 Zn kg/ha produced the highest total dry weight of 370.20g and 93.00g, respectively. The PAN 8816 had the highest panicle mass (105.80g). The relationship between zinc rates, total dry matter, and panicle mass was positive and significant (R² = 1). Therefore, the application of 5.6 Zn kg/ha enhanced the growth of grain sorghum and 10.6 kg Zn/ha improved dry matter accumulation and panicle production. The Enforcer outperformed other cultivars for growth purposes, and PAN 8816 performed the best for panicle production.