The four-year-old victim is still receiving treatment at the hospital.
The fisherman, Edward Quansah pleaded not guilty but the court presided over by Kwame Amoako found him guilty at the end of the trial, the Ghana News Agency (GNA) reports.
Prosecuting, Police Chief Inspector Christina Sampong said that the complainant, Mr Emmanuel Koufie, is the uncle of the victim. They were both living in the same vicinity with the fisherman, Quansah at Ekumfi Narkwa.
According to the prosecutor, Quansah, on March 29 this year lured the victim into a nearby bush and forcefully had sex with her.
He later abandoned her in the bush until some passers-by came to her rescue.
The four-year-old was sent to the Mankessim Roman Hospital but was later referred to the Cape Coast Teaching Hospital where she is still receiving treatment.
Chief Inspector Sampong said a medical report indicated that the victim had been defiled and the case was referred to the Domestic Violence and Victims Support Unit of the Ghana Police Service at Cape Coast.
The Essakyir police were alerted about the incident and Quansah was subsequently arrested.