Water scarcity has adverse effects on the nutrient supply of plants, reducing phosphate availability and exerts significant losses both in crop yield and quality. A pot experiment was conducted to investigate the influence of mycorrhiza on the growth of water-stressed Amaranthus viridis. Seeds of Amaranthus viridis were raised in the nursery and transplanted in the pots. Three species of mycorrhiza namely: Gigaspora gigantea, Glomus clarum and Glomus mossea were inoculated into the pot followed by the application of 5 levels (1 FC, 0.8 FC, 0.6 FC, 0.4 FC and 0.2 FC) of irrigation. The experiment was laid out in a Completely Randomized design. Plant growth parameters were taken 5 weeks after transplanting, while soil physico-chemical parameters were analyzed before and after the experiment using standard procedures. The results obtained showed that the Available Phosphorus in the Soil before planting (SBP) recorded 16.50 mg/kg but increased to 29.50 mg/kg on plants inoculated with mycorrhiza. The pH value of SBP was 4.20 but increased to 5.18 with mycorrhiza inoculation after harvest. At 5 weeks after transplanting, 1FC (Control) produced the highest plant height value, 4.13 cm but not significantly different from other plants with water-stressed plants (0.80 FC – 0.20 FC). Also, greater number of leaves were recorded in plants inoculated with G.gigantea at 0.2 FC (9.33 cm) and G.clarium at 0.4 FC (7.67 cm) and were significantly higher than plants inoculated with G.gigantea at 1 FC and G. mossea at 1 FC, respectively. The inoculation of Mycorrhiza on soils helped to ameliorate the water stress on the plant and enhanced the absorption and utilization of nutrient elements, particularly Phosphorus. Based on comparative assessment of the 3 species of Mycorrhiza used at various levels of irrigation; the Gigaspora gigantea at 0.2 FC outperformed others both in plant parameters and in soil nutrient elements. Therefore, farmers should be encouraged to adopt this method to cushion the deleterious effect of climate change on Amaranthus viridis