Background: The adoption of 12‐h shifts in response to workforce shortages has raised questions about their impact on nurses’ well‐being and patient care quality. While international studies offer mixed findings, little is known about these effects in the Omani context. Aim: To compare the effects of 8‐h and 12‐h shifts on nurse fatigue, quality of life, satisfaction, turnover intention, and perceived patient care in a tertiary hospital in Oman. Methods: A comparative cross‐sectional study was conducted with 100 nurses from Sultan Qaboos University Hospital using self‐administered surveys. Descriptive statistics, t ‐tests, and chi‐square tests were performed to compare outcomes across shift types. A multiple regression analysis was also conducted to assess predictors of quality of life, controlling for shift type, age, gender, marital status, satisfaction, fatigue, and unit assignment. Results: Nurses working 12‐h shifts reported significantly higher levels of fatigue ( p < 0.001; Cohen’s d = 0.82) but also reported higher quality of life ( p < 0.001; d = 0.91) and greater satisfaction with their shift length ( p = 0.001; d = 0.72). No significant differences were found in turnover intention. Patient falls were more frequently reported among 12‐h shift nurses, while other safety incidents showed no significant variation. A multiple regression model predicting QOL was significant ( F (16, 83) = 9.64, p < 0.001, adjusted R 2 = 0.583). Satisfaction with shift was the strongest positive predictor ( β = 0.432, p < 0.001, 95% CI [0.117, 0.287]), while working a 12‐h shift had a significant negative association with QOL ( β = −0.232, p = 0.004, 95% CI [−0.603, −0.117]). Marital status showed a marginally significant positive effect ( β = 0.180, p = 0.051, 95% CI [−0.001, 0.555]). Conclusion: Despite increased fatigue, nurses working 12‐h shifts reported higher quality of life, possibly due to more days off and enhanced work‐life balance. However, elevated fatigue and fall rates warrant caution. The findings underscore the importance of implementing flexible and individualized scheduling policies rather than universally adopting 12‐h shifts. Further longitudinal studies are needed to explore long‐term effects of shift length on nurse and patient outcomes.