In a prospective study of injuries in the 1987 United States Volleyball Association's national tournament, we found 154 injuries in 1520 participants during 7812 hours of play. The injury rate in this study was 1.97/100 hours of play. Before the tournament, the participants' history was taken, and during the week of participation, records were kept of every player who presented with an injury. Players ranged in age from 17 to 60 and competed in five age/gender groups. Females had an injury rate of 2.3 and males had an injury rate of 1.7. The highest injury rate was seen in the men's open division, ages 17 to 35 (2.7), and the lowest rate was seen in the men's Golden Masters, ages 46 and up (1.5). Seventy-nine percent of the injuries occurred during the tournament and 21% were considered to be chronic injuries with an acute exacerbation. The upper extremities accounted for 20% of the injuries. The ankle (17.6%), low back (14.2%), and knee (11%) were the most common injury sites. Strains (36%) and sprains (28%) were the most frequent types of injury. Only eight (5.2%) injuries resulted in more than 5 days of time loss. Two of these injuries involved the knee and two others required surgery. It is likely that in studies relying upon retrospective methods, fewer of the less severe injuries are found, thereby leading to an overestimation of the percentages of knee and ankle injuries and the proportion of severe injuries. The clinician contemplating providing care for a high-level tournament should expect a preponderance of minor injuries occurring in a variety of anatomical locations.(ABSTRACT TRUNCATED AT 250 WORDS)