Although the existence of directional motor biases associated with movement planning and/or execution seems to be widely recognized, single-cell studies and patient studies examining their neuroanatomical correlates have equally produced contradictory and inconclusive findings. Some studies have associated directional motor biases with the premotor cortex, as well as with middle and inferior frontal areas. Other studies have related them to inferior posterior parietal regions. The present study aimed to shed light on this issue by exploring the role of posterior parietal (i.e. right angular gyrus; rAG) and frontal areas (i.e. right middle frontal gyrus; rMFG) in the initiation, planning and execution of directional aiming movements. To that end it was examined whether the application of repetitive TMS over these areas could induce transient difficulties comparable to directional motor deficits in healthy subjects. Fourteen participants underwent a 10-Hz rTMS protocol (600 ms duration) while performing a pointing task with the right hand to either of two lateral targets, under two task conditions (i.e. internally guided [IG; pointing side freely selected] vs. externally guided [EG; pointing side spatially cued]) and two visual feedback conditions (i.e. blindfolded vs. sighted). The experiment consisted of four counterbalanced blocks including sham rTMS, no rTMS, rMFG stimulation, and rAG stimulation. Four main variables were recorded (i.e. reaction times, movement times, frequency of leftward and rightward IG movements, movement accuracy) to measure the effects of rTMS on temporal and spatial aspects of aiming movement. A 3-way ANOVA conducted on reaction times revealed a significant interaction between stimulation condition, task condition and movement direction, F (1.89, 24.64) = 3.99, p = .03. Paired t -tests indicated the presence of significantly longer reaction times for leftward compared to rightward internally guided movements, under conditions of parietal stimulation. Furthermore, a generalized estimating equations procedure with Poisson regression revealed that the interaction involving stimulation site and visual feedback predicted significantly the frequency of leftward internally guided movements (generalized score = χ 2 (3, N = 14) = 8.19, p = .042). This interaction pointed to a reduced frequency of leftward movements under blindfolded conditions compared to sighted ones, when frontal stimulation was applied. Our findings suggest that rAG and rMFG seem both to contribute to the planning and initiation of contralateral aiming movements. Whereas the first one appears to be involved in the generation of a motor intention, pertaining to the selection of the goal and the targets for the action, the latter one contributes to adjusting the initial motor intention with the help of visual information in accordance with the changing demands of the task.