PURPOSE: Defecography is a technique of examining the rectum and anal canal by using fluoroscopy during defecation. This study was done to determine the range of normal findings of defecography in young asymptomatic Korean volunteers. MATERIALS AND METHODS: Twenty-nine asymptomatic young volunteers underwent defecography. Anorectal angle, perineal descent, length and width of anal, rectocele, rectal intussusception and incontience were evaluated. RESULTS: The range of anorectal angle was 82 degrees-149 degrees in resting state, compared to the 63 degrees -116 degrees in squeezing state, and 95 degrees -116 degrees in straining state respectively. The pelvic floor in straining state descended on average of 1.62cm from the inferior margin of ischial tuberosity that its broad range of position from --5.2cm to 0.8 cm implies a wide variation of anorectal angle and periheal descent. Mild degree of rectocele with less than 2cm of depth was found in 12 out of 29 cases. Rectal intussusception was noted in six and rectal incontinence was seen in one case. Formation of rectocele and intussusception during defecation was common in asymptomatic young volunteers. CONCLUSION: The wide range of defecographic measurements warrants the necessity of other complementary studies on anorectal function to improve the diagnostic accuracy. The interpretation of defecographic measurement should therefore be made with caution and should not be used as the sole criteria for seliction of treatment modality.