This report presents the case of a 59-year-old man with the anal abscess caused by fragments of chicken bones. Transrectal ultrasound (TRUS) was performed first to evaluate the anal and perianal region for detection of the lesion and then CT scan was used to show the entire region of the pelvis and anal structures. CT first identified the foreign body within the abscess and then TRUS was able to show hyperechoic foci with acoustic shadowing in the abscess indicated foreign bodies. Diagnosed of abscess with chicken bones was made based on both TRUS and CT and confirmed during the open surgery. CT scan can have a global view of the lesion and surrounding structures while TRUS can provide detail information of the perianal lesion and guide the clinical management.