This paper demonstrates the feasibility of quadrupole moment measurements on isomeric levels populated in projectile fragmentation reactions. The neutron-rich 61Fe(9/2+) [E∗= 861 keV, T1/2= 239(5) ns] isomer was produced and spin aligned by the intermediate energy fragmentation of a 64Ni beam and implanted in a Cd single crystal. Its spectroscopic quadrupole moment
∣∣Qs∣∣=41(6)efm2agrees with mean-field based calculations using the finite-range Gogny force, suggesting a moderately deformed shape characterized by an intrinsic charge quadrupole moment Q0=−85efm2 or
Q0=+115efm2. The present measurement paves the way for future determinations of isomeric quadrupole moments in more exotic nuclei.