Marigold (Calendula officinalis L.) is of great importance due to its benefits in medicinal field and cosmetics industries. The conditions of its cultivation affect its quality. This study was conducted to evaluate the effect of P enhanced by biofertilization using Bacillus megaterium bacteria and Mycorrhiza fungi without or combined with S application on growth parameters and chemical constituents of marigold plant grown on a calcareous soil. The obtained results showed that all the vegetative growth parameters i.e., the plant height, root length, number of flowers/plants, number of branches / plant, number of leaves/ plant increased due to the P application, biofertilization and applied sulfur as compared to the control treatment. Application of P, S and biofertilizers had also beneficial effect on fresh and dry weight in spite of the hard conditions of cultivation in calcareous soil under investigation. Moreover, application of P, S and biofertilizers increased the N, P and K absorption by marigold plants. These results encourage the application of combinations of P, S with biofertilizers (Bacillus and Mycorrhiza) for cultivation of marigold in soils poor in most nutritive elements such as the calcareous soilsto get good and high-quality yield.