Attending professional conferences and seminars is a common business expense, and for self-employed workers those costs are typically deductible. Registration fees for industry conferences, workshops, and professional development seminars are deductible when they are directly related to your current business or profession. Travel, hotel, and 50 percent of meals associated with the conference are also deductible. If you extend the trip for personal sightseeing, those extra days are not deductible. Employees attending conferences they pay for out of pocket generally cannot deduct those costs under current law, making employer reimbursement the better option.