5,318 patients were enrolled, 2,493 male, median age 71 years (5% and 95% inter quartiles 25-91 years). Median lactate level was 1.2 mM (5% and 95% interquartile range 0.6-3.8 mM). Ten-day mortality was 382/5,318 (7.2 %). Ten-day mortality increased with increasing lactate at arrival with 79/1,778 (4.2 %) for lactate 0-0.99 mM, 132/2,182 (5.7 %) for lactate 1.0-1.9 mM, 71/614 (10.3 %) for lactate 2,0-2,9 mM, 29/174 (14.3 %) for lactate 3.0-3.9 mM, 23/87 (20.9 %) for lactate 4.0-4.9 mM, 6/42 (12.5 %) for lactate 5.0-5.9 mM, 10/18 (35.7 %) for lactate 6.0-6.9 mM, 7/11 (38.9 %) for lactate 7.0-7.9 mM and 25/30 (45.5 %) for lactate ≥ 8 mM (Cuzick’s test for trend, p < 0.001). This pattern was more marked in the hypotensive subpopulation. Survival analysis indicated that the increase in mortality was most pronounced within the first five days.