Union density has fallen significantly in recent decades but rumours of the death of unionism appear greatly exaggerated.
New figures show the sector has been growing by about 150 people a week over the past 16 months, above the 130-a-week growth rate in 2011.
Militant membership also appears to be thriving, with a 50 per cent jump in numbers at the construction union over the same period.
The strike-prone maritime union has not boosted its cohort for a couple of years, but that could be because 98 per cent of the eligible workforce are already card-carrying members.
UnionsWA Secretary Meredith Hammat claims the 200,000-strong local membership, together with two million nationally, proves unionism is still the biggest and most powerful social movement in the country.
But what is changing is the composition of the unions.
Last year, the biggest membership increases were enjoyed by those covering white-collar service jobs, such as nurses, teachers, retail employees and council staff, with the construction union the only blue-collar group to record substantial growth.
The changing make-up has also been highlighted by the fact that for the first time there are now more female members in WA than males. According to Bloomberg there were 86,000 women and 77,000 men at the last count in 2012.
Ms Hammat believes the trend will continue.
"It reflects the way work and society are changing, particularly the growth in service industry jobs in WA," she says.
"With the large gender pay gap in WA it's logical that an increasing numbers of women are unionising in order to win better pay and conditions at work."
The gender change is even more stark when considered over the decades.
The number of men who belong to a union today is almost half the 140,000 members in 1990, while women have added slightly to the 1990 count of 79,000.
The Australian Nursing Federation, WA's biggest union with 24,000 members, typifies the growing popularity of white-collar, service sector unions.
Secretary Mark Olson claims new figures soon to be filed with the WA Industrial Relations Commission will show membership has actually hit almost 26,000.
He attributes some of the union's popularity to services which go beyond union core business of enterprise bargaining, such as legal advice and big discounts on mandatory insurances.
The construction union's 50 per cent jump over the past 16 months to late last year, which has boosted its numbers to 14,508, has shocked many.
Not only is the union facing further curbs on its powers under the Abbott Government but since 2005 it has forked out more than $1.135 million in fines imposed by the building industry umpire, Fair Work Building and Construction, for breaking tough industrial laws.
WA's assistant secretary Joe McDonald claims members do not care that their fees are used to pay the fines. In fact, he believes membership has spiked because of the union's militant and sometimes unlawful industrial tactics.
"People want to join a strong union, not a piss-weak union that's in bed with the bosses," he says. "Workers' rights are under attack . . . and they desperately want a union that is going to do something about it."
Mr McDonald was recently fined $193,000 for refusing to leave CITIC Pacific's Sino Iron Ore mine in the Pilbara last February.
"I went up there to expose Chinese workers who were getting paid half the Australian wages," he says. "Sure, we copped it but we didn't look away like everyone else."
Mr McDonald claims the rise in membership vindicates his actions and rejects claims the union has actually done its members a disservice by pricing them out of the international market with high wage demands, not to mention discouraging investment with unlawful stoppages.
Maritime union boss Chris Cain believes the best way to flex union muscle is through legal channels. With the membership's consent, he is seeking to exploit the union's voting rights within the Labor Party in a bid to influence policy and pre-selection.
"Our strength is that our membership wants us to get involved in the ALP," he said.