Over the last 2000 years or so, acupuncture has been utilized to treat a variety of ailments and complaints ranging from headaches and anxiety to nausea and sciatica. In our modern age, acupuncture continues to bring relief from pain, improve immunity and simply makes you feel great! In fact, the World Health Organization (WHO) in 2003 published a list of disorders for which acupuncture has been shown through controlled research trials to be an effective treatment:

Adverse reactions to radiotherapy and/or chemotherapy
Allergic rhinitis (including hay fever)
Biliary colic
Depression (including depressive neurosis and depression following stroke)
Dysentery, acute bacillary
Dysmenorrhoea, primary
Epigastralgia, acute (in peptic ulcer, acute and chronic gastritis, and gastrospasm)
Facial pain (including craniomandibular disorders)
Headache
Hypertension, essential
Hypotension, primary
Induction of labour
Knee pain
Leukopenia
Low back pain
Malposition of fetus, correction of
Morning sickness
Nausea and vomiting
Neck pain
Pain in dentistry (including dental pain and temporomandibular dysfunction)
Periarthritis of shoulder
Postoperative pain
Renal colic
Rheumatoid arthritis
Sciatica
Sprain
Stroke
Tennis elbow

In addition, the following show acupuncture as a promising treatment, but more research is needed:

Abdominal pain (in acute gastroenteritis or due to gastrointestinal spasm)
Acne vulgaris
Alcohol dependence and detoxification
Bell’s palsy
Bronchial asthma
Cancer pain
Cardiac neurosis
Cholecystitis, chronic, with acute exacerbation
Cholelithiasis
Competition stress syndrome
Craniocerebral injury, closed
Diabetes mellitus, non-insulin-dependent
Earache
Epidemic haemorrhagic fever
Epistaxis, simple (without generalized or local disease)
Eye pain due to subconjunctival injection
Female infertility
Facial spasm
Female urethral syndrome
Fibromyalgia and fasciitis
Gastrokinetic disturbance
Gouty arthritis
Hepatitis B virus carrier status
Herpes zoster (human (alpha) herpesvirus 3)
Hyperlipaemia
Hypo-ovarianism
Insomnia
Labour pain
Lactation, deficiency
Male sexual dysfunction, non-organic
Ménière disease
Neuralgia, post-herpetic
Neurodermatitis
Obesity
Opium, cocaine and heroin dependence
Osteoarthritis
Pain due to endoscopic examination
Pain in thromboangiitis obliterans
Polycystic ovary syndrome (Stein-Leventhal syndrome)
Postextubation in children
Postoperative convalescence
Premenstrual syndrome
Prostatitis, chronic
Pruritus
Radicular and pseudoradicular pain syndrome
Raynaud syndrome, primary
Recurrent lower urinary-tract infection
Reflex sympathetic dystrophy
Retention of urine, traumatic
Schizophrenia
Sialism, drug-induced
Sjögren syndrome
Sore throat (including tonsillitis)
Spine pain, acute
Stiff neck
Temporomandibular joint dysfunction
Tietze syndrome
Tobacco dependence
Tourette syndrome
Ulcerative colitis, chronic
Urolithiasis
Vascular dementia
Whooping cough (pertussis)