Arapally Lake is a freshwater lentic ecosystem in Kamareddy district, Telangana, India, for which published information on plankton composition is limited. This study provides a qualitative assessment of the phytoplankton and zooplankton assemblages recorded from the lake and establishes baseline taxonomic information for future ecological monitoring. The research was conducted from June 2025 to May 2026. Surface-water plankton samples were collected during morning hours (approximately 05:30–08:30 h) from three stations representing the inlet, central region and outlet of the lake. Phytoplankton were collected using a 20–30 μm mesh plankton net and preserved in Lugol’s iodine solution, whereas zooplankton were collected using a 55–64 μm mesh net and preserved in 4–5% buffered formalin. Microscopic examination documented six phytoplankton taxa: Spirogyra, Volvox, Radio coccus, Spirulina, Anabaena and Aphanizomenon. The zooplankton records comprised Rotifera, Keratella, Daphnia, Harpacticoida and Ostracoda. The coexistence of green algae, cyanobacteria, rotifers and crustacean zooplankton demonstrates the presence of multiple producer and consumer components in the lake plankton community. However, the available dataset does not include quantitative abundance, diversity indices or verified physicochemical measurements; therefore, trophic status and water-quality condition cannot be inferred reliably from these observations alone. The study should be regarded as a baseline qualitative inventory that can support future seasonal surveys incorporating standardized enumeration, diversity metrics and physicochemical measurements.