You will need a visa to cross sides between Zimbabwe and Zambia. These are available at the border crossings, open from around 6am to 10pm.
You can't get multi-entry visas at the Victoria Falls' crossings; in most cases you need to apply at the embassy in your home country before travelling.
- Crossing into Zambia A day visit costs US$20 for 24 hours (but you'll need a Zimbabwean double-entry to return), a single-entry visa costs US$50 and double entry is US$80.
- Crossing into Zimbabwe A single-entry visa costs US$30 for most nationalities (US$55 for British/Irish and US$75 for Canadian). Double entry is US$45 for most nationalities (US$75 for British/Irish and unavailable for Canadians).
Note that the KAZA Uni-Visa (which formerly allowed travel between the two countries) was suspended in 2016. It's worth checking, though, before you leave to see if it's back in effect.