Today, everything has changed and this has brought a need for learning a second language. Most countries across the world use English as their second/foreign language and the fundamental part of this process is grammar, i.e., the combination of sound, structure, and meaning system of language. A sentence can be composed of several words, clauses, as well as grammatical rules. These grammatical rules should be learned efficiently as they may make a sentence meaningfully different. Hence, the main concern of this study was to find out whether there was any relationship between the grammatical competence and translation ability. To this end, the OPT and translation tests were administrated to 64 young students who studied English translation at Islamic Azad University (Qaemshahr branch). The findings showed that the correlation coefficient between OPT and translation scores was .92 at significance value of P≤.01, which implies a high level of reliability. The results showed a positive relationship between the grammatical competence and translation ability; in other words, those with higher OPT score demonstrate better on translation test than the others. Manuscript profile