The purpose of this study was to assess the presence of the flexion relaxation phenomenon (FRP) in cervical paraspinal musculature in an upright standing posture, and to examine the modulating effect of non-neutral trunk postures on cervical FRP (cFRP). Cervical spinal angles and muscle activation patterns were monitored in 17 participants while performing a neck flexion task in six postures. EMG and angle traces from the flexion trials were used to determine the presence and magnitude of the cFRP (Extension Relaxation Ratio: ERR) and the cervical angles associated with cFRP (onset and cessation angles). The cFRP was observed in the cervical paraspinal muscles (CPS) muscles unilaterally in 11 participants (64.7 %), and bilaterally in 8 participants (47.1 %), across all postures and conditions. Onset angle was lower and ERR was higher in the 45° trunk inclination condition compared to the upright and slumped conditions. ERRs and onset angles were not significantly different in the slumped condition compared to the upright condition. The data from this study contributed to the knowledge base for the underresearched area of cFRP.