Background: With population aging, further asthma research is needed in the elderly. Objective: We assessed the relevance of the controller-to-total asthma medication ratio and its fluctuations over time to identify participants with a subsequent risk of poor asthma-related outcomes among well-characterized elderly women. Methods: We studied 4,328 women with ever asthma (69.6 ± 6.1 years) from the Asthma-E3N study (Etude Epidémiologique auprès des femmes de la Mutuelle Générale de l'Education Nationale), which combined drug claims data since 2004 with prospective individual characteristics. The levels of the yearly controller-to-total asthma medication ratio from 2004 to 2011 were included in latent class analysis to identify groups of women characterized by specific long-term fluctuations of the ratio. Multiple regression models estimated the subsequent risk of uncontrolled asthma, asthma attacks, asthma exacerbations, and poor asthma-related quality of life associated with the level and the fluctuations of the ratio. Results: A short-term (12 months) ratio below 0.5 was associated with a higher risk of subsequent uncontrolled asthma, asthma attacks, asthma exacerbations (odds ratio [95% confidence interval (CI)] = 2.13 [1.41; 3.23], 1.51 [1.01; 2.26], and 2.18 [1.37; 3.44], respectively), and a lower total asthma quality of life questionnaire score (β [95% CI] = −0.49 [−0.68; −0.29]). The analysis of the long-term fluctuations of the ratio identified 5 profiles (“Never regular treatment,” 53.2%; “Persistent high ratio,” 21.8%; “Increasing ratio,” 4.4%; “Initiating treatment,” 8.8%; “Treatment discontinuation,” 11.8%). The subsequent risk of poor asthma-related outcomes was significantly higher in profiles characterized by no or interrupted asthma maintenance therapy over time, compared with the “Persistent high ratio” group. Conclusions: The level and the long-term fluctuations of the controller-to-total asthma medication ratio predict poor asthma-related outcomes in elderly women.