Successfully implemented clinical guidelines can contribute to improvement in the quality of care. In the context of clinical guidelines, quality indicators play an important role. Quality indicators can contribute to the further development and updating of existing guidelines by analysing their results. In addition, these results support internal and external quality improvement activities and supply information on the implementation status of guideline recommendations giving an impression of the actual quality of care. In this paper the data of the mandatory German performance measurement (specimen radiograph of impalpable breast lesions, preoperative waiting time with femoral neck fracture) were analysed in respect to the extent that guideline recommendations have been implemented in clinical care. We analysed a database of 189,756 and 331,087 patients for the quality indicators 'specimen radiograph' and 'preoperative waiting time', respectively. Depending on the quality of the clinical guideline the results varied. After the publication of this recommendation as part of the German high-quality guideline for neoplasms of the breast in 2004 the proportion of radiographic controls of specimens after breast cancer surgery increased from initially 36% to 84% in 2006, and the variance as a measure of the variability of care decreased considerably. By contrast, the percentage of patients with femoral neck fracture undergoing surgery within 48h did not change noticeably (2003: 19%; 2006: 16%). A German high-quality guideline making a clear recommendation for early surgery does not yet exist. Quality indicators of the German mandatory performance measurement system are suitable for measuring the extent to which guideline recommendations have been implemented and for supporting their (further) development.