A carpal coalition that indicates the fusion of two carpal bones resulting from the failure of differentiation is a rare condition compared to the tarsal coalition. The most common carpal coalition is the luno-triquetral coalition, followed by the capitate-hamate coalition. Most of these coalitions are usually asymptomatic. Thus far, only a few cases of a coalition between the scaphoid and lunate with accompanied anomalies in the ipsilateral hand, such as accessory carpal bone or ray deficiency, have been reported. We present, for the first time, a case of a symptomatic isolated scapho-lunate coalition without any accompanying anomalies.