BACKGROUNDS: Furazolidon is a prohibited antibiotic not permissible for use in aquaculture. However, some fish farmers may use it illegally. OBJECTIVES: This study was aimed to investigates the residues of Furazolidone in the muscles of cultured Common Carp. METHODS: One handred cultured Common carp were caught and the Furazolidone content of the fishe's muscle was measured using HPLC technique. Furazolidone was administered experimentally to 60 Common carp through two different procedures. The first procedure was applied by a short term bath while the second approach was considered orally. Sampling from the fishe's muscles was done within 10, 20 and 30 days after exposure. RESULTS: The results of this study showed that Furazolidone was detected in the muscles of 40 cultured fish (40%). This study revealed that Furazolidone had been residually retained in the muscles of fish, using both methods, when examining the 10 day samples. The residues were 3.41±0.76 mg/kg, for the oral administration method, and 2.36±0.54 mg/kg, for the bath. There was no significant difference between these two groups (p>0.05). After 20 days, the residue of Furazolidone was not detected in the short term bath group, but it was detected in the oral group. The results indicated that there was a longer retention of the drug in the oral administration group. Subsequently, 30 days after the drug administration for both groups, no Furazolidone was detected in the fishe's muscles. In the control group, for all samples, there was no Furazolidone residue detectable in the fishe's muscles. CONCLUSIONS: This study showed that Furazolidone may be used in some of the fish farms in the Khozestan Province and at least thirty days are needed for drug to be cleared from their bodies.