Maladaptive daydreaming (MD) is a new proposed mental disorder in which an excessive absorption in vivid, narrative fantasies generates impairments in various life domains. This study aimed to examine the role of traumatic life experiences and immature, neurotic, and mature defense styles in MD. Three hundred and fifty-six Italian adults, ranging in age from 18 to 60 years completed an online survey, including measures of MD, traumatic life events, and defense styles. A multiple mediation model showed that immature, neurotic, and mature defense styles fully mediated the relationship between traumatic life experiences and MD. These findings suggest that clinical interventions for people with a history of traumatic experience who developed MD should aim to help them acquire more adaptive coping strategies to deal with traumatic memories.