Solanum lycopersicum L. is a nutraceutical plant. Tomato yield and morphological features have been improved by irrigation with water treated with static magnetic field (SMF). The effect of magnetically treated water with SMF (20–200 mT) on mineral and nutritional contents in Solanum lycopersicum L. was investigated. Bromatological analyses and minerals contents were determined in tomato fruits harvested after the application of two irrigation protocols (water treated with SMF between 20 and 200 mT and water without SMF treatment as control). Fruits were selected for analysis according to a completely randomized design. Although no significant differences were observed between both groups with regard to bromatological analyses (moisture, total ash, total solids, proteins), an increasing trend was determined for these components in fruits of plants irrigated with SMF-treated water. An increase was detected for potassium (K), calcium (Ca) and cupper (Cu) concentrations in these conditions as compared to fruits of control plants. The SMF treatment of irrigation water improves the nutrient uptake and the water use efficiency in tomato. The nutraceutical value of these fruits was increase and can be considered as an important strategy for future crop production to improve food quality.