Pes anserinus bursitis is inflammation occurring in the knee bursae (small synovial, tissue-lined structures that facilitate the gliding of tissues over other tissues, like tendons moving over bones); the sartorius, gracilis, and semitendinosus muscles; and their associated tendons. Characterized by pain—especially when climbing stairs, swelling, stiffness, weakness, and tenderness, pes anserinus bursitis—also known as anserine or pes anserine bursitis—is common in older adults and females. Athletic activity, diabetes, osteoarthritis, degenerative joint disease of the knee, knee deformities, knee trauma, and obesity can all contribute to the development of this condition. Pes anserinus bursitis responds well to treatment with initial rest and nonsteroidal anti-inflammatory drugs followed by light exercises and stretching. A physical therapist can diagnose pes anserinus bursitis by conducting a series of evaluative tests and then he or she will develop a treatment plan to address the pain and mediate the condition. Treatment plans typically span six to eight weeks and may include a home exercise regimen. To prevent pes anserinus bursitis from occurring or returning, it’s crucial to keep the leg muscles strong. Practice balance, flexibility, and strengthening exercises; learn proper form for any athletic activity; wear proper, supportive footwear; and maintain a healthy weight.