A buckle for use with infant seats and the like having a release button slideably mounted within a hollow buckle housing for simultaneously releasing a pair of male buckle members latched in the housing. A bottom bar is slideably mounted into the housing and provided with locking hooks received within openings provided in the housing for permanently locking the bottom bar to the housing. The bottom bar and male projection members are provided with openings for webbing belts. The housing has integral guide ribs for guiding the male members and bottom bar when inserted into the housing to ensure proper insertion and alignment in the housing. All of the members of the buckle assembly are preferably molded of a suitable plastic material.