Horizon Power says more than 1,000 Karratha customers were without power for two-and-a-half-hours last night after a lightning storm.
The utility says residents in the suburbs of Baynton and Nickol lost power just before 7:00pm (AWST).
Horizon's Tracy Armson says the outage followed a direct lightning strike on one of its insulators.
"All customers were restored at 9:33pm, any overhead infrastructure is always at risk during lightning strikes and severe weather events," she said.
"The outage was caused by a direct lightning strike on one of our insulators located just before the Baynton transformer and that put power out to the Baynton and Nickol suburbs."
© ABC 2013
15:55 EST Two teenage girls have been taken to hospital after lightning strikes near their school oval in Sydney's south-west.