In developing countries, good-quality water is contaminated due to the disposal of untreated municipal and industrial wastewater (WW) into natural water reservoirs. Most of the wastewater is not treated properly according to international standards, and usually is disposed of and/or utilized for irrigation without appropriate treatment. The main hurdles in providing wastewater treatment (WWT) in developing countries include high costs, and the poor design, installation, and operation of conventional WWT systems. Therefore, the present study explores the maize cobs trickling filter-based (MCTF) low-cost WWT option for developing countries like Pakistan, India, and Bangladesh. In this regard, indigenous media trickling filter was designed and developed using maize cobs as packing material for biofilm growth. The MCTFWWT system was continually operated and monitored for six months at constant hydraulic wastewater loading of about 113±2 m³ per m² per day. The experimental data covers winter and summer seasons with temperature variations from 23ºC to 43ºC. System performance was evaluated by means of various WWT parameters, including biological and chemical oxygen demands (BOD₅ and COD), total suspended and dissolved solids (TSS and TDS), turbidity, and color – before and after WWT. Experimental results showed that the MCTF-WWT system successfully removed about 79% BOD and 75% COD on average. The key reason for effective BOD and COD removal was rapid development of microbial film (within the first two weeks). Furthermore, the MCTF-WWT system removed 42-46% TSS, 28-30% TDS, 43-46% turbidity, and 33-37% color. The study concludes that the MCTF-WWT system is an effective and economical WWT option for irrigation/agricultural applications in developing countries.