Film dosage forms containing metronidazole (MZ) were prepared from natural polysaccharides, such as pullulan (PUL) or sodium alginate (ALG), without heating or controlling the pH. The release profiles of MZ from the films were investigated. In the absence of a drug, the casting method resulted in the polysaccharide forming a circular film, and the presence of MZ affected film formation. The thickness of the film was controllable by adjusting the concentration of ALG, and regular unevenness was observed on the surface of film. The film prepared with PUL or ALG readily swelled in dissolution medium, and released MZ with disintegration. The films prepared from the polysaccharides could be promising candidates as dosage forms containing MZ, and would be expected to show drug dissolution in the surface of skin.