We present the low-resolution spectroscopic and UBVRI broad-band photometric investigations of the Type IIb supernova (SN) 2011fu, discovered in UGC 01626. The photometric follow-up of this event was initiated a few days after the explosion and covers a period of about 175d. The early-phase light curve shows a rise, followed by steep decay in all bands, and shares properties very similar to that seen for SN 1993J, with a possible detection of the adiabatic cooling phase. Modelling of the quasi-bolometric light curve suggests that the progenitor had an extended (~1x10^13^cm), low-mass (~0.1M{sun}) H-rich envelope on top of a dense, compact (~2x10^11^cm), more massive (~1.1M{sun}) He-rich core. The nickel mass synthesized during the explosion was found to be ~0.21M{sun}, slightly larger than that seen for other Type IIb SNe. The spectral modelling performed with synow suggests that the early-phase line velocities for H and Feii features were ~16000 and ~14000km/s, respectively. Then, the velocities declined up to day +40 and became nearly constant at later epochs.