In order to determine whether there is a difference in effect on cell morphology and function between two common arthroscopic irrigation solutions, primary cultures of cells derived from the surgically excised human menisci were incubated for 3 or 6 h in lactated Ringer's solution, isotonic sodium chloride solution, or serum-free cell culture medium (negative-control condition). Cell integrity was blindly evaluated by three independent examiners scoring photomicrographs of the cell cultures on a battery of five-point scales for abnormality of cell shape, irregularity of cell membrane, change of cell size and cell density. Cell cultures were also quantitatively assayed by semi-quantitative reverse-transcription-polymerase-chain-reaction for mRNA of alpha1 (I) procollagen, alpha1 (II) procollagen, aggrecan and heat-shock protein 70 to assess functional consequences of exposure to the solutions. There was a statistically significant difference in cell integrity scores between either lactated Ringer's solution or serum-free cell-culture medium and isotonic sodium chloride solution with greater damage to cells displayed. Scores for lactated Ringer's solution did not differ from those for serum-free cell-culture medium. There were no significant differences in mRNA expression level among the treatment conditions. It was concluded that the lactated Ringer's solution better maintained human meniscus cell integrity than the isotonic saline.