Water column surveys and sampling in 2007 and 2009 was conducted to search for hydrothermal plumes over a segment of the Carlsberg Ridge. An evidence for two separate vent fields, one near 3 degrees 42′N, 63 degrees 40′E and another near 3 degrees 41.5′N, 63 degrees 50′E, on a segment that is apparently sparsely magmatic is reported. Both sites appear to be located on off-axis highs at the top of the southern axial valley wall, at depths of approx 3600 m or shallower (approx 1000 m above the valley floor). At the 63 degrees 40′E site, plume sampling found local maxima in light scattering, temperature anomaly, oxidation-reduction potential (ORP), dissolved Mn, and 3He. No water samples are available from the 63 degrees 50′E site, but it showed robust light-scattering and ORP anomalies at multiple depths, implying multiple sources. ORP anomalies are very short-lived, so the strong signals at both sites suggest that fluid sources lie within a few kilometers or less from the plume sampling locations. Although ultramafic rocks have been recovered near these sites, the light-scattering and dissolved Mn anomalies imply that the plumes do not arise from a system driven solely by exothermic serpentinization (e.g., Lost City). Instead, the source fluids may be a product of both ultramafic and basaltic/gabbroic fluid-rock interaction, similar to the Rainbow and Logatchev fields on the Mid-Atlantic Ridge.