- Paint & Painting Supplies, Rockville
- Paint Stores, Rockville
- Pallets & Skids Companies, Rockville - Wholesale - Suppliers
- Paper & Cardboard Manufacturers, Rockville
- Paper Finishers Manufacturers, Rockville
- Passenger Vehicle Dealers, Rockville
- Pentecostal Churches, Rockville
- Personal Care, Rockville
- Personal Legal Services, Rockville
- Personal Services, Rockville
- Personal Watercraft Dealers, Rockville
- Pest Control Services, Rockville - Termite Control, Insects & Bed Bug Treatment - Pest Control Companies
- Pest Control Supplies & Equipment, Rockville
- Pet Food & Supplies, Rockville
- Pet Shops & Supplies, Rockville
- Pets Stores & Pet Supplies , Rockville
|
- Pharmacy & Drug Stores, Rockville - Drugstore - Chemists
- Pipeline Contractors, Rockville - Oil, Water & Gas Pipeline Companies - Installation & Repair
- Pizza Restaurant 1 Of 2, Rockville
- Playgrounds Parks & Trails, Rockville
- Plumbers & Plumbing Contractors, Rockville - Installation, Repair & Replace Services
- Plumbing & Drainage - Supplies & Materials, Rockville
- Plumbing - Sewer & Drain Cleaning & Repair, Rockville
- Presbyterian Churches, Rockville
- Printing Plates & Negatives, Rockville
- Printing Services & Publishing Services, Rockville
- Product Repair Services, Rockville
- Professional, Rockville
- Professional Engineers, Rockville
- Property Operation - Retail Outlet Mall & Establishments, Rockville
- Public Accountants, Rockville
- Public Libraries, Rockville
|