Heavy metals are one of the most frequent environmental pollutants. They come from natural or anthropogenic sources. One of anthropogenic sources of heavy metals in the environment is railway transport whose rapid development and frequent traffic in northwest Croatia leads to environmental pollution and accumulation of metals in plants along the railway line. Metal tin and metalloid antimony are used in railway and transport industry for the production of alloys and as coatings on brakes, which are possible sources of these heavy metals in soil. The main goal of this thesis is to analyse concentrations of tin and antimony in soil and plants along the railway line in northwest Croatia. During June and July 2014 soil samples and plant material were collected at 60 sites. Concentrations of tin and antimony were determined using High Resolution Inductively Coupled Plasma Mass Spectrometry. Their concentrations were determined in soils of different granulometric compositions and in eight species of plants that are commonly found in the researched area. The range of tin concentrations in soil was 3,04 – 97,64 mg/kg and for antimony 0,98 – 51, 98 mg/kg. The results showed that the most polluted sites were the ones at the main train stations where slowdowns and accelerations happen most frequently and at the sites with heavy traffic, like Zaprešić, Varaždin and Žeinci. On the other hand, recorded concentrations of tin in plants were 0,037 – 6,172 mg/kg and antimony values ranged from 0,008 to 1,202 mg/kg. It was also determined that out of eight sampled plant species, ambrosia (Ambrosia artemisiifolia) accumulated the largest amounts of tin and antimony.