| W-554 use Felbamato |
| Waddliaceae use Chlamydiales |
| Waikavirus |
| WAIS-R use Escalas de Wechsler |
| Wakame use Undaria |
| Wakerobin use Trillium |
| Wallabies use Macropodidae |
| Waltheria use Malvaceae |
| Wangiella use Exophiala |
| Warfarina |
| Warnera canadensis use Hydrastis |
| Wasabi use Wasabia |
| Wasabia |
| Washingtón |
| Washingtón D.C. use District of Columbia |
| Waterpolo use Deportes Acuáticos |
| Wautersia use Cupriavidus |
| Wautersia eutropha use Cupriavidus necator |
| Wayk'a use Capsicum |
| Web 2.0 use Medios de Comunicación Sociales |
| Web Semántica |
| Webcasts use Difusión por la Web |
| Webs Semánticas use Web Semántica |
| Wedelia |
| Weisella use Leuconostocaceae |
| Weissella |
| Wellbutrin use Bupropión |
| Weltanschauung use Cosmovisión |
| West Virginia |
| West-Western Blotting use Far-Western Blotting |
| Western Blot use Western Blotting |
| Western Blotting |
| Western Immunoblotting use Western Blotting |
| Wetlands Construidos use Humedales Construidos |
| WGA-HRP use Aglutinina del Germen de Trigo-Peroxidasa de Rábano Silvestre Conjugada |
| Whey use Suero Lácteo |
| Whortleberry use Vaccinium myrtillus |
| Wiesbaden Aqua |
| Wigglesworthia |
| Wikstroemia |
| Wildbad Aqua |
| Wildugen Aqua |
| Wilkstroemia viridiflora use Daphne indica |
| Williopsis |
| Willy-Willy use Ciclón Tropical |
| WIN 59075 use Tirapazamina |
| WIN-59075 use Tirapazamina |
| Winteraceae |
| Winteráceas use Winteraceae |
| Wisconsin |
| Wisteria |
| Witanólidos |
| Withania |
| Withanólidos use Witanólidos |
| Wolbachia |
| Wolfiporia |
| Wolfiporia cocos use Wolfiporia |
| Wolfiporia extensa use Wolfiporia |
| Wolframio use Tungsteno |
| Wolinella |
| Wolinella succinogenes use Wolinella |
| Woodfordia |
| World Wide Web use Internet |
| Wortmanina |
| Wrightia antidysenterica use Kurchi |
| Wu wei zi use Schisandra |
| Wu Zhu Yu use Evodia |
| Wuchereria |
| Wuchereria bancrofti |
| Wuweizi use Schisandra |
| WWW use Internet |
| Wy-21,743 use Oxaprozina |
| Wyethia helenoides |
| Wymox use Amoxicilina |
| Wyoming |
