The exploration of processing patterns is a major topic within the behavioural-cognitive approach to translation and interpreting studies, but existing studies have mainly focused on processing patterns in written translation while largely overlooking other important modes of interlingual transfer, for example sight translation. To fill this gap, the present study investigated processing patterns in rehearsed sight translation from English into Chinese (L1) and vice versa (L2) using eye-tracking technology and examined how translation directions influenced processing patterns in sight translation. It was found that (1) translation students spent more time but invested less cognitive effort in reading the source text in the preparatory reading than the actual sight translation; (2) the coordination time between comprehension and production in sight translation was similar to that with simultaneous interpreting; (3) the processing patterns in each translation direction also showed distinctive differences in both preparatory reading and reading-speech coordination. This was the first study to investigate processing patterns in sight translation that involved two linguistically distinct languages, i.e., English and Chinese, in both L1 and L2 translation and it is hoped that the findings will generate further research along this line.