Inclusion Criteria:

1. Aged 18 - 60 years;
2. Current DSM-IV diagnosis of cocaine dependence;
3. Using at least $200 worth of cocaine within the past 30 days, using cocaine at least 8 days/month, and having positive urine toxicology (BE) during screening;
4. Sexually active
5. Able to provide written informed consent and to comply with all study procedures;
6. Women must be surgically sterile, at least two years postmenopausal, or if of childbearing potential be using a medically accepted method of birth control and agree to continue use of this method for at least 30 days after the last dose of study drug (i.e. barrier method with spermicide, steroidal contraceptive [oral and implanted, including Depo-Provera contraceptives must be used in conjunction with a barrier method], or intrauterine device [IUD]).

Exclusion Criteria:

1. Currently dependent on any substance other than cocaine or nicotine;
2. Not sexually active or engaged in any HRB for the past 30 days;
3. Neurological or psychiatric disorders, such as psychosis, bipolar illness, organic brain disease, dementia, or any diseases that require psychotropic medications;
4. Serious medical illnesses, including but not limited to; uncontrolled hypertension, significant heart disease (including a history of myocardial infarction, angina, mitral valve prolapse, left ventricular hypertrophy, palpitations, and arrhythmia), hepatic disease, renal disease, or any serious, potentially life-threatening or progressive medical illness that may compromise patient safety or study conduct;
5. Received a drug with known potential for toxicity to a major organ system within the month prior to entering treatment including but not limited to; chemotherapeutic agents for neoplastic disease (i.e. methotrexate, vincristine, vinblastine, fluorouracil), agents used for parasitic infections, isoniazid, chlorambucil, dactinomycin, chloramphenicol, immunosuppressive and cytotoxic agents (i.e. cyclosporine, tacrolimus), indomethacin, protease inhibitors, amphotericin B, cephalosporins, aminoglycosides, interferon, and sulfonamides;
6. Clinically significant abnormal laboratory values;
7. Has any disease of the gastrointestinal system, liver, or kidneys which could result in altered metabolism or excretion of the study medication (history of major gastrointestinal tract surgery, gastrectomy, gastrostomy, bowel resection, etc.) or history of chronic gastrointestinal disorders (ulcerative colitis, regional enteritis, or gastrointestinal bleeding);
8. Known hypersensitivity or allergy to modafinil, or receiving chronic therapy with any medication that could interact adversely with one of the medications under study, including propranolol, phenytoin, warfarin and diazepam;
9. Took monoamine oxidase inhibitors (MAOI) within 30 days prior to randomization;
10. Taking or has taken an investigational drug within 60 days prior to randomization;
11. If female and of child-bearing capacity, tests positive on a urine pregnancy test, is lactating, has had three or more days of amenorrhea beyond expected menses at the time of the first dose of study medication, is contemplating pregnancy in the next 6 months, or is not using an effective contraceptive method;
12. Received therapy with any opiate-substitute (methadone, LAAM, buprenorphine) within 60 days of study enrollment.