Purpose <p>Nitrogen (N) is a key macronutrient applied in cropping system to enhance productivity; however, less than 50% of applied N is utilised by crops. Substantial N losses occur through nitrification and subsequent NO₃⁻ leaching, denitrification or NH₃ volatilisation, resulting in economic losses and environmental pollution. This review examines the roles of chemical nitrification inhibitors (NIs) and biological NIs (BNIs) in improving N-use efficiency and mitigating soil- and environment-related N losses.</p> Materials and methods <p>This review synthesizes evidence from laboratory, pot and field studies assessing the impact of NIs and BNIs on soil N transformation processes with a focus on rhizosphere interactions involving microbial activity, plant nutrient uptake, heavy metal bioavailability and interactions with residual agrochemicals across diverse soil and climatic conditions.</p> Results and Discussion <p>NIs delay the oxidation of ammonium to nitrate, thereby improving crop N uptake; however, concerns remain regarding their persistence and non-target effects on soil microbial communities. BNIs offer a promising nature-based alternative by regulating nitrification within the rhizosphere, although their limited diffusion into bulk soil may reduce effectiveness. Both NIs and BNIs influence N cycling, microbial dynamics and trace metal mobilization, with outcomes dependent on soil properties, management practices and environmental conditions.</p> Conclusion <p>NIs are an important tool for enhancing N-use efficiency and mitigating environmental N losses. Future research should focus on mechanistic understanding, non-target impacts and climatic influences to support their sustainable integration into N management strategies.</p>