We will present a new web-based resource for the assessment of language disorders in English monolinguals and Welsh/English bilingual adults with neurological deficits. Although both languages are typically affected in bilinguals, few valid tools are available to accurately and comprehensively assess both languages, and none in Welsh-English speakers. This impedes both accurate diagnosis and therapeutic efforts. The goal of this work was to provide a secure user-friendly platform to allow clinicians to administer and score tests on-line or offline. The battery includes 16 different tests developed to measure the same abilities in Welsh and in English and to be of comparable difficulty in the two languages. These tests assess a range of language skills: spoken word production (picture naming, naming to definition, translation, repetition), reading (reading aloud, lexical decision, paragraph reading) and written production (spelling to dictation, delayed copy, written picture description). The tests manipulate and/or control for key psycholinguistic variables (e.g., word frequency, length, concreteness, Welsh-English similarity, grammatical class, lexicality). In the on-line version, all tests are programmed to allow automatic and standardized presentation of auditory or visual stimuli. The program also records oral or written responses and response times for each stimulus, and provide summary scores broken down by stimulus category. Each test package includes: a) an introductory section explaining the test aims and rationale, b) instructions on how to administer the test, c) scoring instructions and scoring sheets and d) performance indicators (e.g., Z-score) based on control data from 120 neurologically healthy participants (40 English monolinguals and 80 Welsh-English bilinguals, broken down by age, language and educational level. The presentation will include demos of the interface and of computerized test administration and scoring. Note that this new resource is suitable for the assessment of both English monolingual and Welsh-English bilingual adults.