See Rare Diseases by First Letter (W)
- WAGR Syndrome
- Waldenstrom Macroglobulinemia
- Walker-Warburg Syndrome
- Warm Antibody Hemolytic Anemia
- Watermelon Stomach
- Watson Syndrome
- WDHA Syndrome
- Weber Syndrome
- Wegener's Granulomatosis
- Wells Syndrome
- Werner's Syndrome
- Wernicke-Korsakoff Syndrome
- West Nile Encephalitis
- West Nile Virus
- West Syndrome
- Western Equine Encephalitis
- WHIM Syndrome
- Whooping Cough
- Williams Syndrome
- Wilms' Tumor
- Wilson Disease
- Wiskott Aldrich Syndrome
- Wolff-Parkinson-White Syndrome
- Wolfram Syndrome
- Wolman Disease
