'Pedro Sato' guava fruit were treated with 0, 100, 300 or 900 nl 1(-1) of 1-methylcyclopropene (1-MCP) for 3, 6 or 12 h and stored at 25 degrees C. Skin color, pulp color, weight loss, firmness, titrable acidity, ascorbic acid, soluble solids, decay incidence and respiration rate were evaluated. All the treated fruit could be stored for up to 9 days while the non-treated fruit could be stored for only 5 days. The 100 and 300 nl 1(-1) 1-MCP concentrations were inefficient for the 3 h of exposure time, however storage was improved with treatments by 6 or 12 h. 1-MCP at 300 nl1(-1) for 6 or 12 h and at 900 nl 1(-1) for 3 h showed the best results. Fruit treated with 900 n1 1(-1) of 1-MCP for 6 or 12 h did not ripen. (c) 2004 Elsevier B.V. All rights reserved.