Daily and seasonal variations in drinking habits of white-tailed deer (Odocoileus virginianus) were observed in the Coastal Bend area of Texas. Data were collected from February, 1961, to February, 1963, on the Welder Wildlife Refuge. Information regarding drinking behavior was collected by observing deer directly from observation towers located near lakes or water tanks and by making track counts on a cleared, 10-foot wide strip surrounding the water tanks. Both direct observations and track counts were made at all hours throughout the 24-hour period and at all seasons of the year. The following inferences regarding drinking activities can be made from my data. (I) Deer use any water available, but prefer that which is not within fenced enclosures. (2) Deer drink more often in hot seasons than in cold. (3) Peaks of drinking activity are at 7 a.m., 11 a.m., and 4-6 p.m. (4) Deer do not have a specific time of drinking in relation to feeding. (5) Some deer obtain water from leaves of vegetation. (6) Does with fawns are more wary than other deer. (7) Pregnant does drink more frequently than non-pregnant deer. The purpose of this study was to determine daily and seasonal variation of drinking habits of white-tailed deer (Odocoileu8 virginianus). Some information regarding drinking habits of deer in captivity has been reported, but such data for deer in the wild are scarce. The importance of drinking water in the life of deer is emphasized by the fact that watering sites are frequently the centers of home ranges of deer and the presence or absence of water noticeably affects their daily activities. Data collected by other workers indicate that drinking is affected more by temperature than any other meteorological factor (Welch, 1960; Halloran, 1943; Clark, 1953). These data indicate that consumption of water increased directly with air temperature. Data for this study were collected from February 1961 to February 1963, on the Rob and Bessie Welder Wildlife Refuge, San Patricio County, Texas. Surface water was usually abundant over the refuge, especially during wet seasons. Four wet weather lakes were present on the area in addition to 10 small, dirt stock tanks. Moody Creek, which varied from 4 to 15 feet in width, flowed across the western end of the refuge and into the Aransas River, which formed the northern boundary of the refuge. The stock tanks were surrounded by barbed wire fences to keep out cattle, but the lakes, creek and river were not fenced.