Introduction: Recent evidence indicates that the choice of intravenous fluids may affect outcomes in critically ill patients. Methods: We recorded the administration of resuscitation fluids in patients admitted to Australian and New Zealand adult intensive care units (ICUs) for a 24-h period at 6 time points between 2007 and 2013. Changes in patterns of fluid use over this period were determined using regression analyses. Results: Of the 2825 patients admitted to the 61 ICUs on the 6 study days, 754 (26.7 %) patients received fluid resuscitation. Of those receiving fluid resuscitation, the proportion of patients receiving crystalloid significantly increased from 28.9 % (41/142) in 2007 to 50.5 % (48/95) in 2013 (adjusted odds ratio (OR) 2.93; 95 % confidence intervals (CI) 1.35–6.33; p = 0.006); of these, the proportion of patients receiving buffered salt solutions significantly increased from 4.9 % (7/142) in 2007 to 31.6 % (30/95) in 2013 (OR 7.00; 95 % CI 2.14–22.92; p = 0.001). The use of colloids significantly decreased from 59.9 % (85/142) in 2007 to 42.1 % (40/95) in 2013 (adjusted OR 0.34; 95 % CI 0.16–0.74; p = 0.007) due to a significant decrease in the proportion of patients receiving gelatin; 28.9 % (41/142) to 2.1 % (2/95) (OR 0.10; 95 % CI 0.03–0.29; p ≤ 0.001). Conclusion: Fluid resuscitation practice in Australia and New Zealand adult ICUs has changed over the 6-year study period. Crystalloid use increased primarily due to an increase in the use of buffered salt solutions while overall the use of colloid has decreased. ; 9 page(s)