IMPORTANCE In Canada, approximately 81% of residents of nursing homes live with mild to severe cognitive impairment. Care needs of this population are increasingly complex, but resources, such as staffing, for nursing homes continue to be limited. Staff risk missing or rushing care tasks and interfering with quality of care and life. OBJECTIVE To assess the association of work environment with missing and rushing essential care tasks in nursing homes. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study used survey data collected from a random sample of 93 urban nursing homes in Western Canada, stratified by health region, owneroperator model, and facility size, between May and December 2017. All 5411 eligible care aides were invited to participate, and 4016 care aides agreed and completed structured, computer-assisted interviews in person. Analyses were conducted from July 4, 2018, to February 27, 2019. MAIN OUTCOMES AND MEASURES Self-reported number of essential care tasks missed (range, 0-8) or rushed (range, 0-7) in the most recent shift. Two-level random intercept hurdle regressions controlled for care aide, care unit, and nursing home characteristics. RESULTS Of 4016 care aides, 2757 (68.7%) were 40 years or older, 3574 (89.1%) were women, and 2663 (66.3%) spoke English as an additional language. For their most recent shift, 2306 care aides (57.4%) reported missing at least 1 essential care task and 2628 care aides (65.4%) reported rushing at least 1 essential care task. Care aides on units with more favorable work environments (eg, more effective leadership, better work culture, higher levels of buffering resources) were less likely to miss any care tasks (odds ratio, 1.59; 95% CI, 1.34-1.90; P < .001) and less likely to rush any care task (odds ratio, 1.66; 95% CI, 1.38-1.99; P < .001). CONCLUSIONS AND RELEVANCE This study found that rates of missed and rushed essential care in Canadian nursing homes were high and were higher in units with less favorable work environments. This finding suggests that work environment should be added to the list of modifiable factors associated with improving nursing home care, as it may be an important pathway for improving quality of care. Further research is needed to understand associations of missed and rushed care and of improving work environments with outcomes among residents of nursing homes.