This article concerns the influence of arbuscular mycorrhizal symbioses on the accumulation of nitrates and heavy metals in leeks (Allium porrum L.) of the variety Terminal. Leek plants were cultivated under field conditions in 2014 and 2015. A comparison was made of the effects of inoculation with three species of arbuscular mycorrhizal fungus: Rhizophagus intraradices (RI), Claroideoglomus claroideum (CC), and Funneliformis mosseae (FM), plus combinations of these against untreated control. Colonisation in the control was 9.5% in 2014 and 10.7% in 2015. The highest level of colonisation in the treated variants reached 60.0% (RI+FM in 2014) and 58.9% (RI+CC in 2015). The infl uence on nitrates content in leek white shaft tissues was monitored in the variant CC and variants combining two mycorrhizal fungus. The lowest nitrates content was shown in the variants RI+FM in 2014 (44.6 mg·kg^-1) and RI+CC in 2015 (12.2 mg·kg^-1). From the results, we can state that since the climatic conditions highly affected mycorrhizal symbosis development, accumulation of nitrates and heavy metals was significantly differentiated between experimental years.