Abstract Objective Research found a positive connection between emotional intelligence and both borderline personality and posttraumatic growth. Prior research has not examined the combination of emotional intelligence, borderline personality, and cognitive intelligence as predictors of posttraumatic growth (PTG); our research helped fill this gap. Method American adults (N = 402; M age = 38.7 years, SD = 13.0) were recruited from Prolific to complete an online survey including Shipley Institute of Living Scale-2, Assessing Emotions Scale, Posttraumatic Growth Inventory-Expanded, and screening questionnaire for DSM-5 Personality Disorders. PTG was measured in relation to any previous trauma. Participants reported being white (67.2%), African American/Black (9.7%), Asian/Asian American (9.7%), Hispanic/Latinx (9.0%), and other ethnicities (4.5%), and men (48.0%), women (47.8%), non-binary (1.5%), transgender men (1.2%) or women (0.5%), or other genders (0.9%). Results Hierarchical regression revealed that emotional and verbal intelligence significantly predicted PTG, F(2, 391) = 78.54, p < 0.001, adj. R2 = 0.28, 95% CI [0.20, 0.35]. Adding borderline characteristics to the model resulted in significantly greater prediction of PTG, F(3, 390) = 61.22, p < 0.001, F change p < 0.001, and explained 32% of the variance in PTG, adj. R2 = 0.32, 95% CI [0.24, 0.39]. Greater emotional intelligence (beta = 0.535), more borderline personality characteristics (beta = 0.189), and lower verbal reasoning (beta = −0.159) predicted more PTG. Conclusion Our findings suggest that executive functions and borderline characteristics play a complex role in the development of posttraumatic growth after trauma.