Researchers have compared the vocabularies of a range of the world's sign languages in North America, Europe, the Middle East, and Asia, leading to tentative family groupings based on lexical similarity (e.g. Woodward 1978, 1991, McKee & Kennedy 2000). However, little is known about the relationships amongst sign languages in Central Asia, where deaf education programs have short histories and signed language has only recently received scholarly attention. The geographically closest lexical comparisons are Woodward’s (1993) investigation of sign varieties in the south Asian subcontinent as far west as Karachi, Pakistan, and Al-Fityani & Padden’s (2008) and Hendriks’ (2008) comparisons of sign languages in the Arab world as far east as Jordan. In this paper, I explore the relationship of Afghan Sign Language (AFSL) to one foreign sign language with which deaf Afghans have had contact via education programs, namely, American Sign Language (ASL). Woodward (2011:48) suggests that new research on sign languages should begin with lexicostatistical studies. I use lexicostatistical methods to compare basic vocabulary items and present AFSL signs that are initialized with the ASL fingerspelling alphabet, instead of the fingerspelling alphabet used in AFSL. Results of the comparison show that 31.88% (44/138 items compared) of AFSL and ASL basic vocabulary are similar. I argue that this similarity percentage is the result of contact in the early 1990s in one influential education project among refugees in Peshawar, Pakistan. This paper takes a first step towards understanding the relationship of an understudied Central Asian sign language to a foreign sign language imported via deaf education. The level of similarity in basic vocabulary between these languages is unexpected given the short period since the introduction of ASL in Afghanistan. I suggest that these results are indicative of the influence of deaf educational institutions in the formation of signing communities and in the conventionalization of sign language.