Poly(vinyl alcohol) (PVA) was converted into melt flowable derivatives by complexation with a small amount of n-butyl boronic acid (BBA) and phenyl boronic acid (PBA) in dimethylsulfoxide (DMSO), and their thermal properties were examined from a viewpoint of the melt spinning of the complexes. It was found that (1) the melting temperature of the PVA-boronic acid complexes decreases and their degradation temperature increases with increasing the boronic acid content; (2) no gelation occurs for the PVA complexes with BBA and PEA in DMSO; (3) PEA gives a larger melting-temperature depression for PVA than BBA, but the spinnability of the complexes with BBA is much better than that with PEA; and (4) the melt-molded PVA complex fibers can be easily regenerated into PVA fibers with hot water.