Protein calorie malnutrition is a common complication in chronic hemodialysis patients (CHP). Although many factors could promote malnutrition, inadequate nutrient intake seems to be one of the most important. An Appetite and Diet Assessment Questionnaire (ADAQ) was developed, and we have performed a cross-sectional study in 44 CHP to investigate its capacity to predict an inadequate intake. Dietary evaluation was based on a diet diary-assisted recalls (DDAR). On the other hand, the validity of PCR and the differences in the DDAR and ADAQ between the days of dialysis and the days without dialysis were studied. The predictive value of inadequate intake of the ADAQ and the PCR were analysed with the ROC curve. The protein intake was 1.3 +/- 0.3 g/kg/day and the energy intake 29.2 +/- 0.6 kcal/kg/day. The average PCR was 1.14 +/- 0.3. The ROC curve to predict inadequate intake from the ADAQ shows an area under the curve of 0.84 for the protein intake and 0.73 for the energy intake. A cut-off ponit of 18 gives a sensitivity of 100% and a specificity of 44% for the detection of poor protein intake (< 1.2 g/kg/day) and of 74% and 56% for the detection of poor energy intake (< 30 kcal/kg/day). The ROC curve to predict inadequate protein intake from the PCR obtains an area under the curve of 0.81. The cut-off 1.06 gives the best sensitivity (100%) and specificity (64%) for the detection of insufficient protein intake. We did not find any significant difference in the DDAR or in the ADAQ between the days of dialysis and the days without dialysis. Despite the subjective interpretation, the relationship between ADAQ and protein-energy intakes analysed by DDAR was highly significant. The questionnaire is simple and can therefore be used as a screening rest to detect and correct alterations in the diet which could otherwise lead to malnutrition. The determination of PCR gives a good sensitivity and specificity for the detection of poor protein intake, although the results are modified in anabolic or catabolic states which can clinically go undetected. We do not register differences in diet between the days of dialysis and the days without dialysis.