Objective: Prevailing measures of subjective caregiver burden either have no overall summary score or do not consider the relative importance caregivers attach to different dimensions of burden. Our aim was to assess which dimensions informal caregivers perceive as being important to their overall burden from care giving. Design: Cross-sectional. Subjects: Data were pooled from two Dutch samples of primary informal caregivers covering a wide range of chronic care-giving situations: caregivers for stroke survivors ( n = 196) and caregivers for individuals with rheumatoid arthritis (RA) ( n = 131). Main measures: Subjective burden of care giving was assessed using the Caregiver Reaction Assessment (CRA) and the Self-Rated Burden scale (SRB). Results: In the total sample four of the five dimensions of the CRA were found to contribute to the overall subjective burden experienced by informal caregivers. In the individual stroke and RA samples only two of the five dimensions emerged as relevant. SRB scores were significantly higher for caregivers of stroke patients, but no differences were found for the five dimensions of the CRA between the two samples. Conclusions: The dimensions of CRA are not equally important to the overall subjective burden of informal caregivers. To assess overall subjective burden, a measure based on a caregiver's own assessment of burden such as SRB needs to be used in addition to prevailing measures.