Evaluations of speech intelligibility based on a read passage are often used in the clinical situation to assess the impact of the disease and/or treatment on spoken communication. Although scale-based measures are often used in the clinical setting, these measures are susceptible to listener response bias. Automatic evaluation tools are being developed in response to some of the drawbacks of perceptual evaluation, however, large corpora judged by listeners are needed to improve and test these tools. To this end, the NKI-CCRT corpus with individual listener judgements on the intelligibility of recordings of 55 speakers treated for cancer of the head and neck will be made available for restricted scientific use. The corpus contains recordings and perceptual evaluations of speech intelligibility over three evaluation moments: before treatment and after treatment (10-weeks and 12-months). Treatment was by means of chemoradiotherapy (CCRT). Thirteen recently graduated speech pathologists rated the speech intelligibility of the recordings on a 7-point scale. Information on recording and perceptual evaluation procedures is presented in addition to preliminary rater reliability and agreement information. Preliminary results show that for many speakers speech intelligibility is rated low before cancer treatment.