I just tried to purchase tickets online for the Alhambra for later in April and found that they are sold out. Does anyone know of any other options for acquiring tickets?

Was it for a particularly popular day, eg Easter [Sun]Day? We were in Granada at Easter four years ago and went to the appropriate office on the [Easter]Monday morning and booked for the next day, Tuesday. No problem. Perhaps they only release a limited number online. Good luck!

I also don't know of a ticket office that allows you to go around the reservation process... but in case you get stuck, you might consider breaking up your visit into two parts 1) that allows you to visit the Alcazab and gardens in the daytime at a reduced cost and not as in demand as the Palacio and then 2) go back to see the Palacio at night - like 10pm - when you don't have to reserve, just go ticket office reopens. You could go have dinner and come back and the upside is that you get to see the Palacio all lit up at night. I would imagine their website would have info about this.

That can be a very tough time. Are you staying in Granada? Your hotel may be able to help (especially the higher end ones). Good luck and buen viaje!

In case everything else fails, you can book through your hotel a group tour visit, it's more expensive but they always have tickets for the Alhambra