A screen-printed carbon electrode modified with functionalized mesoporous silica nanoparticles (MTTZ-MSU-2) was developed and evaluated for reliable quantification of trace Pb(II) ions by anodic stripping square wave voltammetry in non-pretreated natural waters. The optimal operating conditions were 5min preconcentration time and 120s electrolysis time in HCl 0.2M. The electrode displayed excellent linear behavior in the concentration range examined (1–30μgL−1) with a limit of detection of 0.1μgL−1. The screen-printed carbon modified electrode has long service time and good single and inter-electrode reproducibility. Applicability to spiked drinking water, river water and groundwater was demonstrated without any sample pre-treatment (recoveries between 97% and 106%, RSD 4–7%). On the basis of the present data, mercury-free screen-printed electrodes modified with functionalized mesoporous silicas have the potential to become the next-generation analyzers for decentralized heavy metal monitoring in environmental samples.