Maintenance of hemodialysis graft and fistula patency is becoming even more important as the number of patients with end-stage renal disease increases. There are two major categories of dialysis access: native arteriovenous fistula (AVF) and synthetic arteriovenous graft. Arteriovenous fistulas have superior longevity after maturation and are the recommended type of hemodialysis access, if possible. However, AVFs have a higher rate of primary failure as compared with grafts. Close monitoring has been shown to prolong access survival. Ultrasound is a noninvasive means of imaging for access complications. Ultrasound is sensitive in detection of access or draining vein stenosis. Ultrasound is also useful in the evaluation of other graft or fistula abnormalities, such as pseudoaneurysm, steal, or infection. Careful attention to technical detail is required, and avoidance of several diagnostic pitfalls is necessary.