The choice of antidepressant is largely governed by its side-effect profile. The predictable and idiosyncratic adverse effects of tricyclic antidepressants, selective serotonin re-uptake inhibitors, monoamine oxidase inhibitors and atypical antidepressants are discussed. Information on the newer agents, such as citalopram, milnacipran, mirtazapine, nefazodone and venlafaxine, is included.