A field experiment was conducted in 1999 and 2000 to investigate the effect of different treatments of potable and treated wastewater on the quality of tomato fruit (Lycopersicon esculentum L. Mill) in Jordan. Tomato seedlings (cvs. GS 1 2 and RS 5 8 9 9 5 6 ) were furrow irrigated with different mixtures of potable and wastewater (1:0, 1:1, 1:3, and 0:1). The BOD, and SS of the treated effluent used were 34 and 35mg/l, respectively. Irrigation with treated wastewater did not affect fruit pH, increased their size up to 2cm in diameter, and weight up to 78.7g. Additionally, a decrease of 1.5% in the SSC, 0.59kg in firmness, and 5.1% in weight loss of tomato fruit were recorded. The 0:1 application of treated wastewater resulted in an increased microbial contamination (TC 1.56x10 4 and 4.7x10 2 CFU/100g; FC 3x10 2 and 130 CFU/100g; TBC 188x10 2 and 205x10 2 CFU/100g) on the surface of the fruit (skin) for GS 1 2 and RS 5 9 9 9 5 6 varieties, respectively. There was a negligible contamination on fruit scar, and nil in fruit flesh. Contamination increased exponentially with increasing the proportions of treated wastewater application. Since treated wastewater was highly contaminated with total coliform (up to 42.0CFU/100ml) and total bacterial count (up to 7.820CFU/100ml), hence, contamination was aggravated with increasing the percentage of treated wastewater. It is suggested that the treated wastewater can be used as an alternative for irrigation of tomatoes eaten after cooking, but not for those taken as raw provided that the effluent quality is continuously monitored to avoid contamination.