Absence from work stems from a variety of sources including industrial action, lateness and ill-health. Of these the latter is by far the most significant cause of lost working time: in 1978/79 there were 371 million days of absence due to certified incapacity, contrasting sharply with the contemporaneous loss of just over 15 million days arising from industrial injuries or prescribed diseases and the 9.4 million working days absorbed by industrial stoppages in the calendar year 1978. The volume of sickness absence in 1978/79 was in fact the highest yet recorded and, succeeding the relatively stable levels experienced in the first half of the 1970s it raises once again important questions concerning the economic impact of such absence on individuals, companies and the nation as a whole. These issues will be examined in this Briefing following a review of recent trends and a discussion of the factors underpinning sickness absence from work.