At least in the main tourist areas, Belarus fares relatively well in terms of disabled access for travellers. In Minsk especially, the sidewalks are smooth and broad. Most hotels have lifts, but some public buildings and museums are not fully accessible to people with disabilities or mobility issues. Provincial cities are also pretty friendly, as most feature a central pedestrianised street lined with restaurants and shops.
The situation is less agreeable for locals with disabilities who don't live near the more-accessible centres; many can't leave their Soviet-era apartments on their own. In 2015 Belarus became the last country in Europe to sign the UN Convention on the Rights of Persons with Disabilities.
Download Lonely Planet's free Accessible Travel guide from http://lptravel.to/AccessibleTravel.