Childhood maltreatment is linked to lower quality intimate relationships in adulthood. Although emotional pathways have been considered, there has been less of a focus on cognitive processes that may extend from maltreatment and influence the couple relationship. Additionally, while the role of mindfulness is associated with cognitive and emotional processes as well as romantic relationship outcomes, it remains understudied in survivors of maltreatment. The current study examined mindfulness, posttraumatic stress symptoms, and attributions in a sequential (serial) mediational model linking maltreatment to relationship quality. A sample of 235 adults (89.9% female; M age = 30.43) were recruited from two universities as well as an online sample. Data were analyzed using structural equation modeling. The indirect effects from childhood maltreatment to relationship quality through posttraumatic stress symptoms and attributions were significant. The sequential indirect effect from childhood maltreatment to relationship quality through mindfulness and posttraumatic stress symptoms was significant. Findings from the current study indicate that both cognitive and emotional processes contribute to relationship quality and that mindfulness is a resilience factor reducing posttraumatic stress symptoms. Clinicians are encouraged to use mindfulness-based interventions to reduce posttraumatic stress while also considering the role of attributional processes.