An increase in global population necessitates increased food production. However, drought, soil degradation, and environmental factors have reduced agricultural land. Strategies such as organic amendments, biofertilizers, and nanofertilizers have been explored to promote sustainable agriculture. Nanofertilizers (NFs) are formulations with distinctive properties, including large surface area that enhances nutrient assimilation efficiency, and encapsulated structures that enable sustained release, thereby reducing losses through leaching or volatilization. In addition, NFs act as signaling molecules, strengthening plant defense systems and mitigating stress caused by drought, extreme temperatures, and heavy-metal toxicity. Research on NF formulations has focused primarily on cereals, followed by legumes, and other vegetables and has expanded rapidly with applications through both foliar and soil routes. Among these formulations, dual or multi-nanonutrient types, particularly those containing Zn and Fe, are the most prevalent, followed by macronutrient-based NFs incorporating N, P, and Ca. Bottom-up chemical synthesis remains the preferred method due to its simplicity and reproducibility. Furthermore, advanced NF designs featuring slow-release multinutrients embedded in hydroxyapatite or chitosan matrices show promising results for yield improvement and nutrient uptake. However, the commercial application of nanofertilizers is not yet readily established, mainly due to unresolved safety concerns. Rigorous evaluation, which includes toxicity, dosage, timing, and crop-specific responses, is essential. Future research must value null and adverse findings to provide a balanced understanding of risks for plants, ecosystems, and human health. In conclusion, nanofertilizers represent a promising tool in agricultural systems, whose long-term success will depend on the integration of technological advances with comprehensive assessments of their safety, efficacy, and sustainability.