The objective of the study was to find the impact of accompanying plants (sweet alyssum Lobularia maritima L. and white mustard Sinapis alba L.) upon the growth and chemical composition of broad bean (Vicia faba L.). The assessments were performed by applying the diversified row spacing of broad bean plants and with the use of thinning of the accompanying plant (white mustard) in order to avoid competition. Both accompanying plants beneficially affected broad bean growth. The nitrogen content in the leaves of broad beans accompanied by L. maritima with the retained standard row spacing of 50 cm and S. alba with a 65 cm row spacing significantly decreased (by approx. 6%), which can signify the competition for this element from both plants. The content of macroelements was diverse: in the case of Mg and P, the decreased content was noted, while the contents of Ca and K in some cases increased under the effect of the applied method of protection. The content of microelements and heavy metals usually either did not fluctuate widely, or increased (Fe, Ni, and Al). Only in the case of Zn was there evident decrease in its content in broad beans growing close to L. maritima plants.