Gayle Williams was shot dead by two gunmen in the Afghan capital, Kabul, where she worked for UK-based charity Serve Afghanistan. The Taleban said they killed the 34-year-old for spreading Christianity.
The BBC's Martin Patience in Afghanistan spoke to two British aid workers to find out their feelings about security in the country.
Eleanor Weber-Ballard, 25, works for the Danish Committee for Aid to Afghan Refugees (Dacaar) and has been in Afghanistan for three months.
She said: "I think it's easy to lull yourself into a false sense of security because although you're aware of incidents that happen - there's not a huge sense of danger in the Afghan capital.
But Kabul is a fascinating place to work and the Afghan people are friendly and appreciative - that's the draw
Everybody knows that security restrictions are in place for a good reason but that doesn't stop you getting frustrated.
What happened to Gayle Williams on Monday brings home the dangers of working here and that has a huge impact on how you view the situation.
You start asking questions - 'Where exactly am I going? Is this journey really necessary?'
Some of the places aid workers often go to - restaurants, for example - are packed with other foreigners and you start thinking that these places might be a target.
The security restrictions frustrate people in different ways. I find it difficult that you have to be driven around in a vehicle - and you can't interact with the local population as much as you'd like to.
I came to Afghanistan wanting to experience the country at first hand, particularly with the elections coming next year.
It's tough here sometimes, but I think the rewards outweigh the risks and I'm determined to stay."
Andy Miller, 34, who works for the Aga Khan Foundation, arrived in Afghanistan 18 months ago.
He said: "Daily life is very different in Kabul from Western countries. Most foreigners live in a compound. Everything here takes a bit longer and requires a bit more patience.
In the last six months, the deteriorating security in the provinces close to Kabul has become noticeable.
I perhaps do things differently now because of that. Before the summer, I would have been about a bit more - or walked around the city. But we have quite tight restrictions on movements anyway.
Sometimes I get frustrated but you have to have stamina for a place like this - you can't be easily upset or disturbed.
In Kabul the security seems to come and go - sometimes I feel perfectly safe but this, of course, is when you're most at risk by letting down your guard. But in recent months, I've wondered what the real undercurrent of the security situation really is here.
There are lots of incidents that happen that never make the press. This latest killing, however, I think has shown how dangerous it can be working here.
I think it's the sort of the incident that if you're wavering about coming to Kabul in the first place it might possibly change your mind.
But personally I always think that these are the sorts of the risks that you take when you believe in a place.
I've been gripped by Afghanistan's culture and the history for a long time and want to use my skills to help this country."