Colonization of seagrass leaves was studied using artificial ribbon-like substrates. The study was carried out in a seagrass (Posidonia oceanica (L.) Delile) meadow off the Medes Islands (NW Mediterranean). Artificial leaves of different colors and textures were immersed at two depths (5 and 13 m), and retrieved after 3 and 6 months; epiphytic foraminifera were identified and counted, and the results were compared with those obtained from natural leaves. Although some differences were found in the colonization of the various types of artificial leaf (e.g., smooth, green leaves with float bladder had the highest number of individuals and species) ANOVA and cluster analyses revealed that the type of substrate did not significantly affect the colonization by foraminifera; the main sources of variability were mainly seasonality and, to a minor extent, water depth. Thus, the dominant species were the same in both natural and artificial leaves. The calcareous perforated shells and the trochospiral morphotype were the most abundant, and the dominant biological types were groups B and C, i.e., temporarily or permanently mobile species.