MainStreet Bancshares, Inc. operates as the bank holding company for MainStreet Bank that provides various banking products and services for individuals, small to medium-sized businesses, and professional service organizations. The company offers demand, NOW, money market, savings, and sweep accounts, as well as certificates of deposit; business and consumer checking, interest-bearing checking, business account analysis, and other depository services; and cash management, wire transfer, check imaging, bill pay, remote deposit capture, and courier services. It also provides commercial loans, include government contract receivables, plant and equipment, general working capital, contract administration, and acquisition loans; commercial real estate, real estate construction, and residential real estate loans; and consumer loans comprising term loans and overdraft protection, as well as debit and credit cards.