An R –band photopolarimetric variability analysis of the TeV bright blazar W Comae , between 2008 February 28 and 2013 May 17 , is presented . The source showed a gradual tendency to decrease its mean flux level with a total change of  3 mJy . A maximum and minimum brightness states in the R -band of 14.25 \pm 0.04 and 16.52 \pm 0.1 mag respectively were observed , corresponding to a maximum variation of \Delta F = 5.40 mJy . We estimated a minimum variability timescale of \Delta t=3.3 days . A maximum polarization degree P =33.8 % \pm 1.6 % , with a maximum variation of \Delta P = 33.2 % , was found . One of our main results is the detection of a large rotation of the polarization angle from 78°to 315° ( \Delta \theta \sim 237° ) that coincides in time with the \gamma -ray flare observed in 2008 June . This result indicates that both optical and \gamma -ray emission regions could be co-spatial . During this flare , a correlation between the R -band flux and polarization degree was found with a correlation coefficient of r _ { F - p } = 0.93 \pm 0.11 . From the Stokes parameters we infer the existence of two optically thin synchrotron components that contribute to the polarized flux . One of them is stable with a constant polarization degree of 11 % . Assuming a shock-in jet model during the 2008 flare , we estimated a maximum Doppler factor \delta _ { D } \sim 27 and a minimum of \delta _ { D } \sim 16 ; a minimum viewing angle of the jet \sim 2°.0 ; and a magnetic field B \sim 0.12 G .