This case-control study was conducted to investigate the possibility of pollution caused by reverse osmosis desalination wastewater discharge into the coastal environment from spring 2019 to fall 2020. Five sites (wastewater receiving) and two sites (checkpoint) were selected in Bandar Abbas coast. Seawater, plant waste, and coastal sediments were sampled 63 times at checkpoints and cases. The physical, chemical, heavy metals and plankton were measured. The environmental pollution indices including pollution coefficient, pollution load, enrichment, toxicity potential were determined. The EC and heavy metal concentration (Pb, Cu, Ni, Cd, zinc and Fe) values in the checkpoint were significantly higher than the control stations. The plankton counts in the control stations was more than checkpoint. The pollution indices show low to moderate pollution levels of the banks of the desalination plant. Desalination plants have the potential to adversely affect coastal ecosystems; monitoring and management programs need to be implemented more extensively.