Abstract: Background and Objective: An experiment was conducted to study the morphological and yield characters with 5 genotypes of onion viz., Big Bombay, Special Bombay, Choto Bombay (control), Uz-1 and Uz-2 at the study farm of Sylhet Agricultural University, Sylhet, Bangladesh from November, 2013 to July, 2014 with a view to select the suitable genotypes based on higher yielding abilities in acidic soil condition. Materials and Methods: The experiment was laid out in a Randomized Complete Block Design (RCBD) with 3 replications. Results: Results revealed that the genotype Uz-2 were produced the highest bulb yield (5.85 t ha–1) followed by Special Bombay onion (4.87 t ha–1) and Uz-1 (3.92 t ha–1), while the lowest was found in Choto Bombay onion constituted the amount only 2.21 t ha–1. These high yields were obtained due the highest yield contributing characteristics present among the onion genotypes. The genotype Uz-2 also produced the highest yield contributing characteristics like bulb fresh weight (45.56 g), leaf sheath diameter (1.55 cm) and bulb diameter (4.80 cm) while Special Bombay onion produced the highest bulb length (5.32 cm), bulb dry weight (9.2 g), leaf sheath length (5.1 cm), leaf sheath dry weight (1.9 g) and leaf blade dry weight (2.24 g). Similarly, the genotype Uz-1 produced the third highest bulb yield but obtained the maximum leaf blade diameter (1.17 cm), leaf blade length (85 cm) and fresh weight of leaf blade (53.25 g). The study finding will help for further study in onion crop to find out the genotypic effect which is suitable for acidic soil environment. Conclusion: Considering yield and yield contributing characters, the genotype Uz-2 can be selected as the best genotype for growing in acidic soil at Sylhet region of Bangladesh. Therefore, the findings of the present study will help the breeders for further yield improvement of onion in acid soil.