This study analysed the energy balance and greenhouse gas emissions in the production of the ‘Maraş 18’ walnut cultivar. Energy use efficiency indicators and greenhouse gas emission rate calculations were performed for the 2022–2023 production season in ‘Maraş 18’ cultivar production. Here, total energy input was calculated as 19,962.04 MJ ha−1 and total energy output was calculated as 30,145.68 MJ ha−1. Energy use efficiency, specific energy, energy efficiency and net energy were determined as 1.51, 11.86 MJ kg−1, 0.08 kg MJ−1 and 10,183.63 MJ ha−1, respectively. The percentages of direct energy, indirect energy, renewable energy, and non-renewable energy inputs in production were calculated as 47.02%, 52.98%, 7.39%, and 92.61%, respectively. The largest input, accounting for 39.30% (7846.08 MJ ha−1), was the use of chemical fertilisers. The total greenhouse gas emission was calculated to be 1067.81 kgCO2eqha−1, with a greenhouse gas emission rate of 0.63 kgCO2eqkg−1. The energy use efficiency for the 2022–2023 production season indicates that ‘Maraş 18’ walnut cultivar production is profitable.