An empirical study was designed to identify which perceptual-motor, cognitive and personality factors may underlie both acquisition of a signed language as a B language and development of signed language interpreting skills. If abilities that are potentially needed are found, a previous assessment of candidates' potential for developing signed-language interpreting skills could be useful in identifying which students are likely to obtain good results during training. Perceptualmotor and cognitive skills, personality factors and academic background were hypothesized as possible predictors of success. Results showed that perceptual-motor and cognitive abilities are more important than personality traits in predicting proficiency in learning a signed language and developing signed-language interpreting abilities. Perceptual-motor coordination is the most reliable factor for predicting signed language proficiency, followed by other cognitive and personal factors.