The purpose of this study was to determine the effect of seed rate on the growth and yield attributes of the wheat crop (Triticum aestivum L.) variety Mazar-99 under the agro-climatic conditions of Takhar province, Afghanistan. The experiment was implemented at the research farm of Agriculture Faculty of Takhar University in winter seasons of 2018-2019 with the specific objective of finding out the effect of five seeding rates as the treatment on growth and yield parameters of Mazar-99 variety of wheat. Randomized Complete Block Design (RCBD) was selected as an experiment design with 4 replications and 5 seeding rates viz. 80, 100, 120, 140 and 160 kg/ha made up treatments. Data on growth and yield parameters were collected and analyzed using Analysis of Variance (ANOVA) for Randomized Complete Block Design (RCBD). The result obtained from the current study reveal that all growth and yield characters were remarkably affected by seeding rate and seed rate of 100 kg per hectare of wheat variety Mazar-99 performed better with respect to different growth and yield parameters such as spike length, number of tillers, number of spike at each plant, leaf area, a total of spikelets per spike and stem girth, grain number/spike, the weight of spike, the weight of grain per spike, grain crop yield, straw crop weight, 1000-grain weight, and biological yield. Whereas 80 and 120 kg/ha were the second-best seeding rates after the 100 kg/ha. However, 160 kg/ha seed rate showed only superiority in plant height, but 140 kg/ha did not show any special superiority in any growth and yield characteristic evaluated in Takhar agro-climatic condition. Thus, a seeding rate of 100 kg per hectare could be recommended to the farmers for better wheat production in Takhar agro-climatic situation in North-Eastern Afghanistan.