Neuronal ceroid lipofuscinoses (NCLs) represent the most common cause of neurodegeneration in children.  The CLN3 form is characterized by progressive vision loss, epilepsy, dementia, behavioral difficulties, and motor impairment. The Unified Batten Disease Rating Scale (UBDRS) is a disease-specific rating scale that was developed to assess the natural history of NCLs.  Validity and reliability of the UBDRS has been established in a large North American CLN3 cohort. This study was performed to determine the validity and reliability of the UBDRS in an independent sample. 13 individuals with CLN3 disease were evaluated by 5 examiners at the University Medical Center Hamburg Eppendorf (UKE). One rater (JWM) served as the reference standard.  The other raters were physicians with expertise in various forms of Batten Disease.  After formal training, 13 individuals (age 16.5 +/- 5.6 yrs) were evaluated in parallel by the 5 raters.  Inter-rater reliability was assessed with Intra-class Correlation (ICC) analysis.  The relationship between age and severity was compared to previously published data. The ICC for the 5 independent raters was 0.92. When evaluated as a function of participant age, slope was 3.06 points/year, comparable to the data published by Kwon et al., 2011 showing a slope of 2.86 points per year with a 95% CI of 2.27–3.45. These results demonstrate excellence reliability and additional evidence for validity of the UBDRS in an independent sample.  The UBDRS is a valid and reliable rating scale that can used to assess the severity and rate of progression of CLN3 disease.