Infiltration of local anaesthetic into an area before incising with a scalpel is common surgical practice. After a chance observation that a carbon steel scalpel rusted within minutes of contact with local anaesthetic, the corrosive effects of normal saline and local anaesthetic solutions on carbon and stainless steel surgical blades were investigated. After a series of preliminary studies with approximately fifty scalpels, we used a semi-quantitative technique using digital photography to demonstrate the corrosive effect of local anaesthetic on twelve carbon steel scalpel blades. These blades were exposed to saline, lignocaine and bupivacaine, and the surface changes were recorded and compared. A stainless steel blade was also photographed for comparison. All blades were found to rust in all three solutions, but there were considerable differences in the rate of progression and the surface area of the blade affected. Corrosive effects occurred rapidly on the carbon steel blades when exposed to all solutions, the process beginning within minutes of immersion. The overall effect was most marked with blades partially immersed in local anaesthetic. The stainless steel blades were much more resistant rusting, but had started to corrode by twelve hours, and were substantially rusty after 24 hours. Total immersion in solution produced minimal effects and thus rapid corrosion requires an air-liquid interface. This paper demonstrates the surprisingly rapid speed of corrosion of the standard carbon steel scalpel blade when exposed to solution, especially in the presence of an air-liquid interface. This phenomenon has not been previously described and has a number of implications. In the developing world, scalpels may be re-used, and in such circumstances avoidance of contact with local anaesthetic may increase the life of the blades. In addition, excess tissue damage from the poor performance of a rusted blade may occur and may tattoo the skin with rust. Furthermore, there is evidence to suggest that iron oxides may have carcinogenic and cytotoxic properties. Carbon steel blades are often preferred as they can be manufactured sharper and cheaper, however, we would recommend either their replacement after contact with local anaesthetic, or the use of stainless steel blades in particular circumstances.