The wide range of scalenus minimus muscle incidence reported in the literature along with the plethora of fibromuscular structures that may appear in the interscalene triangle, having various terminologies, were the reasons to conduct the present study questioning the reported high incidence of this supernumerary scalene muscle. Seventy-three Greek cadavers were dissected and examined for the presence of a scalenus minimus muscle. It was found unilaterally in three of 73 (4.11%) cadavers studied. The literature review, concerning its incidence, revealed a wide range between 7.8 and 71.7 per cent, which cannot be attributed only to racial variation. Thus, there is a matter whether other variations of the scalene muscles are considered as a true scalenus minimus muscle. Recognition of this muscle is important not only for anatomists, but also has clinical significance for the diagnosis of the thoracic outlet syndrome. Surgeons performing scalenectomy and anesthesiologists during interscalene brachial plexus block should keep in mind the anatomical variations of this region.