Of course. Stats influence your combat effectiveness:
Strength: Will improve your chance to hit the enemy in melee and increase your damage output.
Dexterity: Will improve your armour class, reflex saves, and tumble checks (so it will prevent damage) and increase your chance to hit with ranged attacks (or attacks with light melee weapons, of you have weapon finesse)
Constitution: Will give you more hit points and fortitude saves (so will prevent bad things to happen and let you stay on your feet longer). Spellcasters need it for concentration checks to keep casting spells even under bad conditions (being threatened by enemies, being hit while casting the spell, and so on)
Intelligence: Wizards use this for spellcasting, giving them more spells and making their spells harder to resist
Wisdom: Clerics, Druids, Rangers and Paladins use this for spellcasting. Also increases will saving throws (so it prevents bad things to happen to you) and perception based rolls (so enemies have a harder time tricking you)
Charisma: Bards and Sorcerers use this for spellcasting, and innate magic abilities usually use it as well.
Beyond that, most ability scores open up new possibilities (Int will let you access Combat Exptertise and follow-up feats), and all have out-of-combat benefits as well.