<p>This study presents a field evaluation of an iron-net–amended ceramic filter (INCF) for arsenic (As) removal from groundwater in Bangladesh. The INCF was constructed by integrating an iron net with a low-cost ceramic filter housed in a clay bucket. Twelve single-stage, four double-stage, and two control filters were installed in arsenic-affected areas representing a wide range of groundwater chemistry. The INCF reduced As to the drinking-water standard (50&#xa0;µg/L) in groundwater containing moderate to high dissolved iron (5–16&#xa0;mg/L) and arsenic levels of 200–300&#xa0;µg/L. In contrast, performance was significantly reduced in low-iron groundwater (&lt; 2&#xa0;mg/L). Arsenic removal efficiency increased markedly in double-stage INCFs compared to single-stage units. Removal of iron (Fe), phosphorus (P), and manganese (Mn) was also efficient in both single- and double-stage INCFs. The aeration step shifted groundwater from reducing to oxidizing conditions, promoting oxidation of Fe²⁺ to Fe³⁺ and As(III) to As(V). The resulting formation of hydrous ferric oxide (HFO), together with As(III) oxidation, facilitated As removal through adsorption and coprecipitation. XPS analysis revealed extensive passivation of the iron-net surface by iron hydroxides, phosphate, silicate, and calcium scaling. This passivation suppressed Fe⁰ corrosion, limited Fe²⁺ release, and reduced arsenic removal efficiency. Overall, the INCF performs effectively in iron-rich groundwater, but its efficiency in low-iron waters could be improved by incorporating more reactive iron media to accommodate diverse groundwater conditions.</p>