"A" Phobias

Let's first define what phobia is. As per MedicineNet.com, Phobia is "An unreasonable sort of fear that can cause avoidance and panic. Phobias are a relatively common type of anxiety disorder. Phobias can be treated with cognitive behavioral therapy, using exposure and fear-reduction techniques. In many cases, antianxiety or antidepressant medication proves helpful, especially during the early stages of therapy."

Ablutophobia - Fear of bathing, cleaning or washing.
Acerophobia - Fear of sourness.
Achluophobia - Fear of darkness.
Acousticophobia - Fear of noise.
Acrophobia - Fear of heights. (Altophobia)
Aeronausiphobia - Fear of vomiting.
Agateophobia - Fear of insanity.
Agliophobia - Fear of pain.
Agoraphobia - Fear of open spaces or of crowded places.
Agyrophobia - Fear of streets or crossing the street.
Aichmophobia - Fear of needles or pointed objects.
Ailurophobia - Fear of cats.
Alektorophobia - Fear of chickens.
Algophobia - Fear of pain.
Alliumphobia - Fear of garlic.
Allodoxaphobia - Fear of opinions.
Amathophobia - Fear of dust.
Amaxophobia - Fear of riding in a car. (Hamaxophobia, motorphobia, ochophobia)
Ambulophobia - Fear of walking.
Amnesiphobia - Fear of amnesia.
Amychophobia - Fear of getting scratched.
Anablephobia - Fear of looking up.
Androphobia - Fear of men.
Anemophobia - Fear of air drafts or wind.(Ancraophobia) 
Anglophobia - Fear of England or English culture, etc.
Angrophobia - Fear of anger or of becoming angry.
Anthrophobia - Fear of flowers. (Anthophobia)
Anthropophobia - Fear of people or society.
Antlophobia - Fear of floods.
Anuptaphobia - Fear of staying single.
Apeirophobia - Fear of infinity.
Aphenphosmphobia - Fear of being touched. (Haphephobia)
Apiphobia - Fear of bees.
Apotemnophobia - Fear of persons with amputations.
Aquaphobia – fear of water.
Arachibutyrophobia- Fear of peanut butter sticking to the roof of the mouth.
Arachnephobia - Fear of spiders. (Arachnophobia)
Arithmophobia - Fear of numbers.
Arrhenphobia - Fear of men.
Arsonphobia - Fear of fire.
Asthenophobia - Fear of fainting or weakness.
Astraphobia - Fear of thunder and lightning.(Astrapophobia, Ceraunophobia, Keraunophobia)
Astrophobia - Fear of stars or celestial space.
Asymmetriphobia - Fear of asymmetrical things.
Ataxophobia - Fear of disorder or untidiness.
Atelophobia - Fear of imperfection.
Athazagoraphobia - Fear of being forgotten or ignored or forgetting.
Atychiphobia - Fear of failure. (Kakorrhaphiophobia)
Aulophobia - Fear of flutes.
Aurophobia - Fear of gold.
Autodysomophobia - Fear of one that has a vile odor.
Automatonophobia - Fear of ventriloquist's dummies, animatronic creatures, wax statues - anything that falsely represents a sentient being.
Automysophobia - Fear of being dirty.
Autophobia - Fear of being alone or of oneself.
Aviophobia - Fear of flying. (Aviatophobia)

Sources: 
http://phobialist.com/
http://en.wikipedia.org/wiki/List_of_phobias