An experiment was conducted to investigate the effects of Bacillus amyloliquefaciens LFB112 in the diet on growth of broilers and on the quality and fatty acid composition of broiler meat. 440 1-day-old Arbor Acres male broiler chicks were randomly allocated into five dietary treatments with eight replicates in a completely randomised design for 42 days. The treatments were as follows: basal diet (control) or the basal diet supplemented with 107 colony-forming units (CFU) B. amyloliquefaciens/kg (B7), 108 CFU B. amyloliquefaciens/kg (B8), 109 CFU B. amyloliquefaciens/kg (B9) or 40 mg aureomycin/kg (antibiotic). The results showed that B. amyloliquefaciens-supplemented groups had greater (P < 0.05) average daily gain during Days 1 to 21, Days 22 to 42 and Days 1 to 42, and improved (P < 0.05) feed conversion rate during Days 1 to 42 compared with the control. Broilers in the B7 and B9 groups had higher (P < 0.05) average daily feed intake than those in the control group in all experimental phases. Broilers fed either B. amyloliquefaciens or antibiotic diet showed higher (P < 0.05) a* value, b* value and lower L* value in the breast muscle than those in the control group. Dietary B. amyloliquefaciens supplementation increased (P < 0.05) the contents of C14:1, C16:1c, C18:1t, C18:1c, C20:1n-9, total monounsaturated fatty acids, C18:2c, C18:3n-3, C20:2n-6, C20:3n-6, C20:3n-3, C20:4n-6, C20:5n-3, C22:6n-3 and total polyunsaturated fatty acids as well as ratio of polyunsaturated fatty acids to saturated fatty acids in breast muscle and the concentrations of C17:1, C20:1n-9, C18:2t-9, t-12, C20:2n-6, C20:3n-6, C20:3n-3, C20:4n-6, C20:5n-3 and C22:6n-3 in thigh muscle of broilers. The results indicated that B. amyloliquefaciens improved broilers’ growth performance, meat quality and fatty acid composition.