Psychological ownership (PO) pertains to an individual’s feeling of being psychologically tied to and possessive of an object or a target. PO has been studied as a factor related to workplace outcomes–for example, a sense of PO in one’s organization is associated with work performance and job satisfaction. The motives for psychological ownership seem to come from human fundamental needs: efficacy, self-identity, and belongingness. Other dimensions include accountability and territoriality. The present study investigates the relationship between PO and insecure adult attachment dimensions: avoidance and anxiety. Avoidantly attached individuals tend to be self-reliant and autonomous, use work as a distraction, and are thus hypothesized to have more PO. Anxiously attached adults tend to have lower self-esteem than non-anxious individuals, prefer to work with others, have interpersonal concerns interfering with productivity, and are thus hypothesized to have lower levels of PO. Analyses were conducted on 288 full-time employees. Results revealed that anxiously attached individuals tend to have higher levels of overall PO. Both anxious and avoidant attachment positively relate to the territoriality subscale of PO. Anxious attachment is positively associated with the self-efficacy subscale whereas avoidant attachment is negatively associated. Avoidant attachment is negatively correlated with accountability and belongingness subscales. Ultimately, this study provides more information about the personality traits associated with PO, which is in turn associated with work performance and job satisfaction. The results can be used to implement interventions to improve the dynamic of the workplace.