A street curb drain filter is comprised of U-shaped brackets for attaching to an inside wall of a street curb drain adjacent an inlet. A horizontal retaining bar is attached to the outer ends of the brackets. The lower edge of a horizontally elongated flexible net is attached to the retaining bar. The upper edge of the net is connected to the interior ceiling of the drain with eye bolts and S-hooks. A horizontally elongated debris basin is supported within the brackets. A filter media pack is positioned inside the basin adjacent a perforated outer wall of the basin. Water flowing from the street into the drain is directed through the filter. When runoff is relatively light, debris flowing into the drain is collected inside the basin. When runoff is relatively heavy or when the basin is clogged, debris bypassing the basin is filtered by the net.