A multi-walled carbon nanotubes (MWCNTs) were used for modification of two solid electrode types, glassy carbon electrode (GC), which is widely used for modification in electroanalysis, and, for the first time, paraffin impregnated graphite electrode (PIGE). The optimization of MWCNT/PIGE and MWCNT/GC electrodes was carried out by altering ultrasonication parameters (ultrasonication time, ultrasound generator performance, and dispersing agent). The preparation of modified electrodes was investigated. The most electrochemically sensitive MWCNT/GC electrode was prepared with nanotubes sonicated for 30min and the most sensitive MWCNT/PIGE for 20min, both using ethanol/water solution as dispersing agent and 500W ultrasound generator performance. Both electrodes were successfully used for analysis of lead performed by DC voltammetry. Current responses were measured for the concentration of lead (II) in range from 1x10-5 to 5x10-5moldm-3 for MWCNT/PIGE and also MWCNT/GC electrode.