This study reports on the results of a research program carried out to validate the C-Test amongst Afghan EFL learners. One hundred advanced English majors were administered two different language tests namely a language proficiency test (composed of listening, reading, and writing) and a C-Test composed of four different texts to measure the overall language ability of the participants. Various analyses were used to examine the validity and reliability of the C-Test. The C-Test correlated highly with the criterion measures. The results of the study confirmed that the C-Test is a reliable and valid test that can be used as a general English language proficiency test among Afghan students of English as a foreign language.