Evidence is limited regarding cannabinoid use among total joint arthroplasty (TJA) patients, despite increased availability and popularity for treating chronic pain. The authors hypothesized that preoperative cannabinoid use increased and opioid use decreased during a 6-year interval in total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients, and also asked whether complications were associated with use of these substances. This retrospective, single-institution study reviewed electronic medical records and the Veterans Affairs Surgical Quality Improvement Program (VASQIP) database for TJA cases from 2012 through 2017. Primary outcomes were the prevalence and trends of active cannabinoid and opioid use, as determined by routine preoperative urine toxicology screening. Multivariable regression analyses were conducted to investigate a secondary outcome, whether there was an association between cannabinoid or opioid use and postoperative complications. A total of 1778 operations (1161 TKAs and 617 THAs) performed on 1519 patients were reviewed. The overall prevalence of pre-operative cannabinoid and opioid use was 11% and 23%, respectively. Comparing 2012 with 2017, cannabinoid use increased from 9% to 15% (P=.049), and opioid use decreased from 24% to 17% (P=.040). Cannabinoid users were more likely to be taking opioids than nonusers (P=.002). Controlling for age, sex, surgery type, and American Society of Anesthesiologists score, cannabinoid use was not associated with 90-day readmission, infection, reoperation, or other VASQIP-captured complications. Laboratory testing indicated a much higher prevalence of cannabinoid use among TJA patients than previously reported. During a 6-year period, cannabinoid use increased more than 60%, and opioid use decreased approximately 30%. These findings indicate that cannabinoid use did not appear to be associated with perioperative complications. [Orthopedics. 2021;44(x):xx-xx.].