The Markit Stanbic Bank Kenya Purchasing Managers' Index (PMI) rose to 59.1 in October from 56.3 in September, well above the 50.0 mark that separates growth from contraction.
October's reading is the highest since the survey began in January 2014.
"Output and new order growth accelerated to the sharpest on record as lockdown restrictions, associated with the coronavirus disease 2019 (COVID-19), eased during October," the survey compilers said.
Kenya eased some restrictions aimed at containing the spread of the virus in September, like the sale of alcohol in bars and restaurants. It kept a curfew in place for another two months but shortened its hours.
As of Tuesday, Kenya had 57,093 confirmed COVID-19 cases and 1,039 deaths, according to health ministry data.
The government has expressed concern over rising cases and deaths in October, during which other countries have reintroduced some COVID-19 restrictions to combat a second wave of the pandemic.
"With lockdowns being reimposed in some major international trading partners, new orders could ease over the coming months especially if external demand falters," said Jibran Qureishi, head of Africa Research at Stanbic Bank.
"Moreover, with COVID-19 cases also on the rise nationally, the risk of further containment measures pose downside risks to economic activity, prompting us to be cautious."
(Reporting by George Obulutsa; Editing by Catherine Evans)
