This study was undertaken to assess the mineralization of nitrogen (N) in rice soils amended with organic residues under flooded condition. A lab incubation study with a 3x3 factorial design (two replications) was conducted with three rice soils (Joydebpur, Faridpur, and Thakurgaon) receiving the following treatments: 1) control, 2) rice straw (Oryza sativaL.), or 3) pea vine (Pisum sativumL.). The organic residue (25 mg straw g‐1soil) was mixed with soil and glass beads (1:1, soil to beads ratio), and transferred into a Pyrex leaching tube, flooded and then incubated at 35°C for up to 12 weeks. The soils in the leaching tubes were leached (while maintaining flooded condition) at 1,2,4, 8, and 12 weeks with deionized water for determination of NH4‐N, NO3‐N, pH, and Eh. Nitrogen mineralization in soils amended with rice straw was somewhat different than that of soils treated with pea vine. Soil treated with rice straw had a higher N mineralization rate than soils treated with pea vine, which was due to a lower carbon (C):N ratio for rice straw. The potentially mineralizable N pool (No) in soils amended with rice straw and pea vine under flooded conditions, estimated using a 1st order exponential equation, were 7 to 15 times, and 3 to 9 times greater for rice straw Novalues and pea vine, respectively, than the control. The KNvalues for unamended soils ranged from 0.35 to 0.52 mg N kg‐1wk‐1and rice straw and pea vine treated soils were from 0.75 to 1.22 and 0.46 to 0.58 mgN kg‐1wk‐1. The lower Noand KNvalues in pea vine treatments suggested there was greater immobilization of N than in rice straw treatments.