The Deloitte WA Index recorded its biggest one month growth in five years in January, increasing by 10.6% or $8.5 billion.
The lion's share of the growth was recorded by Woodside, whose market capitalisation increased by almost $4 billion to $30 billion.
The growth in WA stocks almost tripled the growth of the ASX All Ordinaries which grew by 3.64%.
At January 31, 2006, the combined market capitalisation of WA-listed companies increased to $93.2 billion.
Deloitte Managing Partner Keith Jones said that global commodity prices were the key drivers in the massive growth of WA stocks in January.
"Gold, nickel and oil prices all increased by more than 10% in January and this growth drove the WA market to record levels," Mr Jones said.
"The price of oil rose sharply by 11.3% to close the month at US$67.92 a barrel while nickel grew by 12.9%."
Major monthly movers in January were Paladin Resources (up $642 million or 73.2% to $1.519 billion), Marion Energy Limited, formerley Carpenter Pacific Resources, (up $29.6 million or 37.8% to $108 million) and Jabiru Metals Limited (up $57.7 million or 135.2% to $100 million).
Mr Jones added Paladin's increase came on the back of the first two forward sale contracts of yellow cake from its Langer Heinrich uranium mine in Nambia.
The Engineering and Construction sector also performed well, recording an average growth of 20% for Janaury. Strong performers were United Group, Monadelphous and Macmahon.
The January editon of the Deloitte WA Index includes for the first time an analysis of the global commodities prices on a month-by-month basis. It shows an increase across the board.