Although unhelmet motorcyclists were only slightly more likely to be hospitalizion motorcyclists overall they were more severely injured ,nearly three times more likely to have been head injured and four times more likely to have been severely or critically head injured than helmeted riders. Unhelmet riders were also more likely to be readmitted to a hospital for follow-up treatment and to die from their injuries. The average hospital stay for unhelmet motorcyclists was longer and cost more per case the cost of hospitalization for unhelmet motorcyclists was 60% more overall (3.5 vs 2.2 million).