| Pleurothallis rufescens (Rolfe) Schltr., 1921 |
| Pleurothallis rufobrunnea Lindl., 1859 |
| Pleurothallis saccatilabia C. Schweinf., 1940 |
| Pleurothallis samacensis Ames, 1923 |
| Pleurothallis sanchoi Ames, 1923 |
| Pleurothallis sanguinolenta Garay & W. Kittr., 1985 |
| Pleurothallis scariosa (Lex.) Lindl., 1842 |
| Pleurothallis schiedei Rchb. f., 1850 |
| Pleurothallis schlechteriana Ames, 1923 |
| Pleurothallis schulzeana Schltr., 1918 |
| Pleurothallis schweinfurthiana L.O. Williams, 1956 |
| Pleurothallis scopula Schltr., 1910 |
| Pleurothallis segoviensis Rchb. f., 1855 |
| Pleurothallis segregatifolia Ames & C. Schweinf., 1924 |
| Pleurothallis sertularioides (Sw.) Spreng., 1826 |
| Pleurothallis setosa C. Schweinf., 1941 |
| Pleurothallis sororia Schltr., 1912 |
| Pleurothallis spathulata A. Rich. & Galeotti, 1845 |
| Pleurothallis spectabilis Ames & C. Schweinf., 1925 |
| Pleurothallis stenostachya Rchb. f., 1845 |