The objective of the research study performed was to determine the concentrations of Mg, Ca, Na, K, P, and Fe in breast muscles of ROSS 308 broiler chickens subjected to various pre-slaughter handling procedures in summer. The pre-slaughter handling procedures consisted in providing the broilers, during a period of seven days before slaughter, with a herbal extract composed of goat’s rue (Herb. Galegae), stinging nettle (Herb. Utricae), lemon balm (Fol. Melissae), and common sage (Fol. Salviae). The supplement was administered in feed or drinking water. After the seven-day period, the chicks were transported 100 km, 200 km, and 300 km. It was found that the pre-slaughter handling procedures applied impacted the mineral content in the breast muscles of broiler chickens. Compared to the control group and to chickens provided with the herbal extract in their drinking water, an insignificant increase was reported in the mineral content in the breast muscles in broilers having received this herbal extract mixed with their feed for seven days prior to slaughter. A similar or an increased level of mineral element concentrations was evidenced in the breast muscles of chickens transported 100 km and 200 km. However, in the muscles of chicks travelling at a distance of 300 km, the content of the mineral elements decreased compared to the not transported group.