Hundreds of Thai transgender women proudly showed off their medical certificates today April 6 allowing them to dodge national service.

The annual ritual has become a trend for ladyboys - the affectionate local term for men who now live as women - to openly show they are women.

Military chiefs in Thailand only allow males to take part in the compulsory army service, with leaders drawing names from a hat every year of men over the age of 21 for a gruelling two-year stretch.

Trans women across the country - who still have male birth certificates - are legally required to attend the events.

However, in recent years, trans women have treated the event as a show of pride by wearing glamorous dresses and make-up to distinguish themselves from the men. They can show medical certificates proving their new gender, which excuses them from conscription as the army does not allow them.

Pictures and video show young lads and transgender girls waiting to be called by officers at enlistment offices around the country as the drive continues until April 20.

Transgender Ekasit Chanthongthong, who identifies by her female name 'Nong Earth,' 21, wore a white off-shoulder dress to the centre.

She said: 'I worked as a bartender in Phitsanulok city centre. I'm very excited because it is my first time reaching the age of selection.

'I would not want to serve in the military because my mind and body are those of a woman, but I still came here and prepared a medical certificate as proof that I was born as a Thai man.

'I'm proud of who I am and I'm proud that I don't have to join the army. I wouldn't enjoy it there.'

Another transgender woman present at the centre, Ariyathat Deemi, 21, or Nong Latte, came to make a waiver for the first time as she was still studying.

She said: 'I've been very excited. It is my duty as a Thai man to be present, but I'm still studying so I brought all of my documents for proof.'

Transgender shop worker Somchai, or Nong Candy, said: 'I'm not a man, I'm a ladyboy and I'm proud of that.'

She joked: 'I can understand why they don't let me in the army... the guys would be distracted by my beauty!'

Thai males can avoid national service if they are studying at university but they still have to take education classes on the military for three years. They can also get a discounted one-year option if they join voluntarily.

Thailand's military includes the Army, the Royal Navy and the Royal Air Force and has around 300,000 state employees.

The country's government was also formed by the military following a coup in 2014 and the prime minister is career soldier General Prayut Chan-o-cha.

Around eight per cent of the country's population are believed to be in the LGBT demographic but Thai laws still impose some restrictions on their rights - including banning them from joining the army.