Psychosocial factors have been found to relate to parental reflective functioning (PRF), a parent's ability to mentalize about themselves and their child. Relations between maternal psychosocial risk factors and PRF were investigated in a community sample. A sample of mothers (n=146) was assessed for risk factors when infants were 6months, infant temperament was assessed using an observational measure, and PRF was assessed with the Parent Development Interview-Revised (PDI). PRF was measured again with the Parental Reflective Functioning Questionnaire (PRFQ) when children were 4years (n=105) and 5years (n=92), with an additional sample of mothers (n=48) tested at these two timepoints. Results showed that in infancy, total maternal psychosocial risk related to lower PDI-PRF; regression analyses highlighted low socioeconomic status, unplanned pregnancy, and low maternal anxiety as independent predictors of lower PDI-PRF. PDI-PRF scores at 6months did not relate to PRFQ scores, but PRFQ subscales showed stability over time from age 4-5. Results are discussed with regard to the impact of maternal psychosocial risk and infant temperament on PRF and the stability and concordance of PRF measures.