Individuals with Parkinson's disease (PD) feature reduced walking speed. However, the relationship between walking speed and different task conditions remains unclear. This study aims to investigate walking speed in single and dual-task conditions among individuals with PD. This cross-sectional study analyzes baseline data from a controlled clinical trial developed at “Reference Center for Aging and Movement” (CREM) in Brazil. A total of 15 subjects, 67.1±8.1 years, 9 men, recruited through community advertisements, and diagnosed with PD scoring 1 to 3 on the Hoehn and Yahr (1967) scale. Participants walked along a straight-line course, with timing measured over the central ten meters to calculate gait speed in meters per second (m/s). Conditions assessed in the test: 1) participants walked at their self-selected speed (SWSS) under standard conditions without additional tasks; 2) motor-cognitive dual task involving arithmetic problem-solving; and 3) motor-cognitive dual task of composing a message on a cell phone. OpenSim was utilized for collecting biomechanical data, while statistical analyses were conducted using JASP. The mean values were: SWSS (4.10±1.12 km/h), arithmetic (3.71±0.98 km/h), and cell phone (2.82±1.11 km/h). SWSS exhibited differences compared to arithmetic (p=.043) and cell phone (p<.001), while arithmetic also differed from cell phone (p=.005). The activity of typing on a cell phone combines fine motor skills, stabilization of the shoulder girdle and relative visual deprivation, involving multiple sensorimotor integration tasks and cognitive demands. Gait speed is significantly affected by these demands, and other motor parameters of locomotion still need to be investigated.