Recently published guidelines advise limiting opioids prescriptions for acute painful episodes to a 3-day supply; however, there is little literature available to quantify patterns of opioid use after an ED visit. Additionally, the number of pills included in a 3-day supply is not quantified in guidelines and may vary widely (eg, a 3-day supply of hydrocodone-acetaminophen using typical dosing intervals could be 12 tabs (1 PO Q6 hours) or 36 tabs (2 PO Q4 hours)). We sought to describe opioid consumption patterns after an ED visit for acute pain and quantify the proportion of patients who would exceed a 3-day supply at the commonly dispensed quantity of 12 tabs. As part of a larger interventional study promoting the safe use of opioids after an ED visit to an urban academic hospital (>88,000 visits), patients completed a 10-day medication diary documenting their medication consumption (including both analgesics and other home medications). Patients were enrolled if they were age >17 years, received a prescription for hydrocodone-acetaminophen and did not chronically use opioids. Patients were included in this analysis if they returned the completed medication diary and had a discharge diagnosis in 1 of 4 categories: back pain, kidney stone, fracture or musculoskeletal injury (non-fracture). Patient demographics and pain scores are reported. Opioid consumption is described using daily number of pills consumed and daily morphine milligram equivalents (MMEs) both for the sample overall and by diagnosis group. Additionally the proportion of patients continuing opioid use is reported by post-visit-day both overall and by diagnosis. 191 patients with the diagnoses listed above returned completed medication diaries [45 (24%) back pain, 52 kidney stone (27%), 54 fracture (28%), 40 (21%) musculoskeletal injury (non fracture)]. Mean Age a 6 years (sd 14), 57% female. Pain scores on ED presentation were high and remained high post discharge (eg, Day 1: 7 (N=161), Day 2: 7 (N=143), Day 3: 6 (N=122)). Mean quantity of opioid pills prescribed: 16 tabs. On the day of discharge (Day 1), 85% of patients consumed an opioid at home (87% back pain, 73% kidney stone, 93% fracture, 88% musculoskeletal injury) with a mean tabs consumed of 1.7 (sd 1), resulting in 11.2 (7.9) MME (13.9 (11.4) MME back pain, 9.5 (5.2) MME kidney stone, 10.7 (6.9) MME fracture, 11.1 (6.6) MME musculoskeletal injury). The proportion of patients consuming opioids on subsequent days decreased on the day after discharge for patients with kidney stones (42%) and fractures (81%), remained stable for those with musculoskeletal pain (90%) and increased for those with back pain (91%). Among those patients taking pills on the first 2 days after discharge (Day 2 and Day 3) the MME consumed increased (15 (10.2) and 15.6 (12.2) MME, respectively) before decreasing on subsequent days (Day 4: 13.5 (11.5) MME, Day 5 13.3 (9.2) MME). Only 7.7% of kidney stone patients consumed more than 12 pills; whereas 42.2% of back pain patients consumed more than 12 pills in the 10 days post-discharge. 81% of patients had leftover pills (66% back pain, 96% kidney stones, 74% fracture, 87% musculoskeletal injury). In this sample, pill consumption varied by illness category; however, overall patients were consuming low quantities of pills and the majority had unused pills 10-days after their ED visit. Further data could help support prescribing tailored by diagnosis and minimize unused pills.