The quality of the general practitioners' setting of diagnoses using codes from the International Classification for Primary Care (ICPC) is important, because these codes are used for purposes of quality development, research and public health statistics. It is uncertain, however, to what extent these diagnoses present a correct picture of the content of and reasons for the consultations and the prevalence of illness in the population. The objective of this study was to identify the extent to which the general practitioners' use of diagnostic codes correlates with the content of the patient record notes.A total of 23 general practitioners from five different medical centres in Agder county participated in the study. The patient record notes from all patient contacts over two working days in 2013 were reviewed by two experienced general practitioners who assessed the degree of correspondence between the content of the patient record notes and the concomitant ICPC diagnostic codes.A total of 1 819 patient contact were assessed, and for 1 591 of these (87.5 %) it was possible to assess the correspondence between the patient record notes and the diagnosis. We found good correspondence for 693 (85.3 %) consultations and 321 (69.9 %) simple contacts with issuance of a prescription. For simple contacts with no issuance of a prescription there was good correspondence for 213 (83.9 %), although 144 of a total of 398 (36.2 %) could not be assessed because the patient record notes were absent, too brief or imprecise.The diagnoses made during consultations corresponded well with the patient record notes examined in this study. The results may indicate that caution should be exercised in including simple contacts in the data on diagnoses in public statistics. The findings should be followed up in larger-scale and more representative national studies.