With tire and road wear particles (TRWP) generated by automotive traffic on roads also tire-related chemicals (TRCs) become airborne. A long-term monitoring of TRCs in roadside aerosol (PM₁₀) was performed for 14 months (119 samples). In total, 40 TRCs were determined by LC-MS/MS in the samples, belonging to phenylendiamines, guanidines, benzothiazoles, ureas and amines. Median volume concentrations were 0.61 pg/m³ for 6-PPD and 2.9 pg/m³ for 6-PPDQ, with 19 of the studied chemicals showing higher concentrations (benzothiazolesulfonic acid 41 pg/m³, diphenylguanidine 90 pg/m³). TRC volume concentrations varied by about four orders of magnitude over time, with precipitation being the single most influential factor, further modulated by temperature, sunshine, wind, and reactive trace gases. Traffic-normalized roadside aerosol concentrations of TRCs were calculated and allow extrapolation to other urban sites. TRC mass concentrations in tire tread particles were one to two orders of magnitude higher than in roadside aerosol and dominated by parent chemicals rather than their transformation products. In rural aerosol TRC concentrations were up to one order of magnitude lower. This study shows that a broad range of TRCs is present in roadside aerosol, with their concentration being highly variable in time and governed by a complex interplay of emission, transport and transformation.