The purpose of the present study was to quantify factors which contribute to the absenteeism of nursing personnel and affect staffing patterns. Absenteeism in a general hospital was studied for the period 1975-1990 in relation to the number and level of nursing personnel, the number of discharged patients in the same period, and the existing relevant policy. The variables were analyzed by the multiple regression method having an initial estimator the existing situation in 1990 and what is expected for the year 2000. The results showed that the mean value days of absenteeism for each registered and assistant nurse in 1975 was 22.4 days and in 1990, 51.9 days, sickness raised from 12.6 days in 1975 to 16.6 in 1990, maternity from 9.1 in 1975 to 25.3 in 1990, educational leave for registered nurses was 0.02 in 1975 and 3.8 in 1990 and for assistants 2.1 in 1985 and 17.3 in 1990 due to the new policy, and social fringe benefits raised from 0.71 days in 1975 to 3.65 in 1990. The expected rate of absenteeism by the year 2000 will be 67 to 83 days per person, an increase by 56% in relation to 1990 data.