This pilot randomized controlled trial in Kazakhstan aimed to adapt and test the feasibility of a couple-based HIV/STI risk-reduction intervention (CHSR) for couples who are injecting drug users (IDUs). The study examined the preliminary effects of the intervention versus an attentional control wellness promotion (WP) condition on HIV risk behavioral outcomes among 40 couples who are IDUs (n = 80 participants). Compared with WP participants, CHSR participants were significantly more likely to increase condom use and decrease unsafe injection acts at the 3-month follow-up. This pilot trial demonstrates the feasibility and preliminary effects of the CHSR in reducing drug-related and sexual HIV risks.