Empirical evidence from well designed studies into the effects on carers of caring for a person with HIV is lacking. This study investigated the correlates of carers' burden and adjustment to their caring for a person with HIV. Thirty-four carers and their HIV-infected patients were interviewed and completed self-administered scales. Measures included two psychosocial adjustment indices, a Problem Checklist (burden) and two patient health status indices. The most common elements of carer's burden were distressing emotions, relationship difficulties, somatic symptoms, and grief. Demographic variables, patient's HIV stage, nature of caregiving relationship and duration of caregiving were unrelated to carers' burden or adjustment. However, living arrangement was found to be significantly associated with carers' burden, with those carers co-residing experiencing more burden than those living apart from the patient. Carers' coping strategies were only weakly related to carer's adjustment and burden. The patients' emotional and existential concerns were strongly positively related to carers' burden and all domains of adjustment, while patients' instrumental concerns and measures of patients' health status were positively related to carers' burden. As predicted, patients had significantly poorer levels of adjustment than carers. The findings supported the use of a reciprocal determinism approach for understanding the relationship between the patient and carer and adjustment outcomes.