Introduction: The effect of erectile dysfunction (ED) on sexual planning behaviors and outcomes in men taking phosphodiesterase type 5 inhibitors (PDE5Is) is not well studied. Aims: To assess sexual habits, behaviors, and treatment-related outcomes of PDE5I-treated men with ED. Methods: This cross-sectional observational study recruited men aged 30 to 70 years with mild-to-severe ED from 8 diverse countries (the United States, the United Kingdom, Italy, Russia, Turkey, Israel, China, and Japan) to complete an approximately 15-minute survey. Differences were evaluated using bivariate analyses, and data were summarized using descriptive statistics. Main Outcome Measures: Self-reported data were collected for demographics, health characteristics, treatment, sexual habits, ED severity, ED-specific quality of life, and treatment satisfaction. Results: The survey was completed by 1,575 men. Mean frequency of sexual intercourse was 5.7 times/month. Overall, 87.1% of men always, often, or sometimes planned for sexual activity. Of those planning in advance, 32.8% and 40.6% agreed or strongly agreed that they plan for specific days of the week and times of day, respectively. Sexual planning habits were similar for patients taking short-acting vs long-acting PDE5Is. The most commonly cited reasons for planning sexual activity were needing time to take medication (48.4%), needing to make sure medication has taken effect (43.4%), convenient time for sexual activity (34.9%), and needing the partner's agreement (33.4%). Mean Self-Esteem and Relationship Questionnaire total score was 56.4. Conclusions: The differences in ED burden and sexual planning behavior observed across countries were not influenced by the type of PDE5I being taken, suggesting that cultural differences are an important factor when considering types of ED treatment. These findings provide a better understanding of burden, sexual habits, planning behaviors, quality of life, and treatment-related outcomes among PDE5I-treated men with ED in 8 Western and non-Western countries and may aid healthcare providers in selecting optimal treatments. Goldstein I, Giraldi A, Maculaitis MC, Real-World Assessment of the Impact of Erectile Dysfunction on Sexual Planning Behavior and Health- and Treatment-Related Outcomes Among Men in 8 Countries. J Sex Med 2020;8:338–349.