It is advisable to have a valid passport that will last for six months of the date you plan to leave Uganda. In case your passport get lost or stolen while in Uganda, it is much easier to get a replacement that is when you have a photocopy of the important pages.
For Nationals of most countries it is a must to have a visa to enter Uganda and although previously it was better to buy these well in advance at any Ugandan embassy or High Commission abroad, it’s easier to acquire the visa upon arrival and much as some queuing is inevitable, it’s a straightforward procedure and cheaper since one gets there visa there and then of course after they have queued.
For a standard single entry visa valid for three months costs US$ 50, student visa’s cost US$ 100 and multiple entry visa’s (6-12 months) cost US$ 100, (24 months) US$150 and (36 months) US$200. Once in East Africa, a single entry visa for Uganda, Kenya and Tanzania allows you to visit either of the other two countries (when you’ve met their visa requirements) without and return without having to apply for another visa. However, this is different for Rwanda and Congo. If you leave Uganda for these countries (say to track gorillas), you must purchase another visa on re-entry but if you intend to spend seven days in Uganda before leaving again, then you purchase a transit visa. Otherwise you will incur more for another visa and on top of that most foreign nationals require a visa to enter Rwanda which can also be bought on arrival at any border.
Visa rulings are subject to change, so make sure you check the current quotations with your travel agent or Ugandan diplomatic mission before you travel. Immigration authorities will now generally stamp your passport for a maximum of one month upon arrival but you can have this extended to three months at any immigration office although in Kampala you will be asked to provide a letter from a sponsor or hotel at which you are staying which is all standard procedure but in Jinja it can be extended without any of this. Multiple entry visas are only issued at Immigration Head Quarters in Kampala. Illegal stay is fined US$ 30 per day.