Sulfide-enriched environments are not typically considered to be sites that support abundant eukaryotes, yet it is known that plentiful and relatively diverse protistan and metazoan fauna inhabit at least one modern bathyal sulfidic site (Santa Barbara Basin, California). This contribution adds to our knowledge of eukaryotic communities inhabiting sulfide-enriched deep-water sediments by presenting data from Soledad Basin (off the western coast of Baja California, Mexico) and Cariaco Basin (off Venezuela). Results indicate that, when considered at the appropriate scale, the density of eukaryotes in Soledad Basin was comparable to that of Santa Barbara Basin. Eukaryotic biovolume and abundance were dominated by foraminifera at all three sites. Unlike the Santa Barbara Basin assemblage, Soledad eukaryotic abundance and biovolume were not dominated by eukaryotes with associated putative symbionts. An undescribed polychaete found in Cariaco Beggiatoa-laden sediments had bacterial ectobionts. Sub-millimeter life-position analysis indicated that Soledad eukaryotes concentrated within the top 2 mm even when the bottom-water oxygen concentration was relatively high (2.7 µM). Observations suggest that the eukaryotic fauna of a Thioploca-dominated site (Soledad) varied substantially in taxonomic composition and sub-millimeter life positions from Beggiatoa-dominated sites (Cariaco and Santa Barbara).