Local rice cultivar Mentik Susu has potential as a superior variety that can be developed on tidal swamp lands with acid sulfate soils, which are extensive yet underutilized in Indonesia. The main challenges of cultivation on such lands include low nutrient availability and suboptimal soil conditions for plant growth. This study aimed to evaluate the agronomic characteristics and yield performance of Mentik Susu rice cultivated organically under acid sulfate soil conditions. The research was conducted from January to July 2025 in the Agroecotechnology Greenhouse, Faculty of Agriculture, Universitas Lambung Mangkurat, using a pot experiment with the System of Rice Intensification (SRI) planting method and kiambang bokashi fertilizer applied at five dosage levels. Observed parameters included plant height, number of productive tillers, root length, panicle length, number of grains per panicle, 1,000-grain weight, and grain weight per clump. The results showed that Mentik Susu exhibited good agronomic performance, with average plant height of 103.59 cm, 24.41 productive tillers, panicle length of 27.283 cm, number of grains per panicle of 193.72, and a 1,000-grain weight of 25.697 g. The potential grain yield ranged from 2.34 to 8.59 t ha?¹. Overall, these findings indicate that the application of organic fertilization using kiambang bokashi can support the growth and productivity of Mentik Susu rice on tidal swamp lands. Therefore, organic cultivation of this variety has the potential to enhance food security and promote the sustainable utilization of suboptimal lands.