Cattle feedlot manure loses 75-80% of N, mainly in the form of nitrous oxide (N₂O) and ammonia (NH₃). Mitigating these emissions is a global environmental concern. Laboratory incubation study was conducted for 30 day period in 9 chambers (0.49 x 0.33 x 0.33 m) at 20±1 ^oC, to evaluate the effects of lignite and willow-wood biochar, on NH₃ emissions from cattle manure. Synthetic manure matrix (rockwool + synthetic cattle urine + urease enzyme) was filled into the chambers and treated with lignite and biochar, at 30 t/ha rate. Synthetic urine was applied into the chambers, at a rate of 0.43 l/m². Experiment was arranged in a RCBD design with 3 replicates. NH₃ from chambers was trapped in a 0.05 M H₂SO₄ solution and manure medium was analysed routinely for NH₄⁺ and urea retention, organic C and N, ¹⁵N, moisture content and pH. Highest NH₃ emissions were recorded during the first 2-3 days of incubation. Ammonia losses from manure amended with lignite were significantly (p < 0.01) lower (30 times) than biochar amendment and control. Lignite amendments resulted in significantly (p < 0.01) higher NH₄⁺ retention (73%) compared to biochar (2%) and control (8%). Lignite achieved the maximum retention of NH₄⁺ within 6-7 days and then stabilised over the rest of the duration. Urea hydrolysis was completed within 3-4 days in lignite and biochar treated chambers, and this can be related with the highest emissions of NH₃ within first 2-3 days. Lignite treated medium maintained a pH of 4.5 throughout the experiment while biochar and control chambers resulted a pH of 8-9. Thus lignite shows a great potential in reducing NH₃ emissions from cattle urine compared to the wood-based biochar.