Recent evidence shows that highly skewed sex ratios at birth are observed not only in China and India, but also for a number of countries in the Southeast Europe and South Caucasus - a region that has seen eruptions of conflicts following the collapse of communist regimes. Yet, the role of conflict has been largely overlooked in the relevant literature on ”missing girls”. We argue that conflict and group survival concerns can exacerbate the initial son bias and lead to relatively more male births once low fertility levels and access to ultrasound technology are given. We test our hypotheses in the context of Nagorno Karabakh conflict between Armenia and Azerbaijan. First, individual-level survey analysis from Armenia shows that relatively stronger concern over national security and territorial integrity is significantly associated with son preference. Second, difference-in-difference panel analysis of community-level census data shows that once ceasefire breaches between Armenia and Azerbaijan intensified, Armenian communities closer to the conflict region exhibited relatively higher sex ratios at birth.