The Collaborative International Dictionary of English v.0.48:

Hurtful \Hurt"ful\, a.
   Tending to impair or damage; injurious; mischievous;
   occasioning loss or injury; as, hurtful words or conduct.

   Syn: Pernicious; harmful; baneful; prejudicial; detrimental;
        disadvantageous; mischievous; injurious; noxious;
        unwholesome; destructive. -- Hurt"ful*ly, adv. --
        Hurt"ful*ness, n.
        [1913 Webster]

WordNet (r) 3.0 (2006):

hurtful
    adj 1: causing hurt; "her hurtful unconsidered words"
    2: harmful to living things; "deleterious chemical additives"
       [syn: deleterious, hurtful, injurious]

Moby Thesaurus II by Grady Ward, 1.0:

75 Moby Thesaurus words for "hurtful":
   acute, afflictive, agonizing, atrocious, baleful, baneful, biting,
   corroding, corrosive, corrupting, corruptive, counterproductive,
   cramping, cruel, cutting, damaging, deadly, deleterious,
   destructive, detrimental, disadvantageous, disserviceable,
   distressing, excruciating, gnawing, grave, griping, hard, harmful,
   harrowing, harsh, hurting, injurious, lethal, malefic, malevolent,
   malicious, malign, malignant, mean, mischievous, nasty, noisome,
   noxious, ominous, painful, paroxysmal, pernicious, piercing,
   poignant, poisonous, prejudicial, pungent, racking, scatheful,
   severe, sharp, shooting, spasmatic, spasmic, spasmodic, spiteful,
   stabbing, stinging, tormenting, torturous, toxic, unkind, venenate,
   veneniferous, venenous, venomous, vicious, virulent, wounding