Yes, Vietnam visa is must for any kind of tourists or travelers taking Vietnam trip. The normal way of getting Vietnam visa formality is done from the Vietnam embassy. However, if you are a citizen of Guyana, you are required to obtain visa to enter in the country of Vietnam.  Since, until now no Vietnam visa are available in Guyana, in this situation you will get visa on arrival at the international airport of Vietnam through their immigration department over online or you can find some embassy office in your nearby countries only. Therefore, you need to worry if you will get proper service over online or not. The traditional method of obtaining Vietnam visa may be time consuming and tedious. 

Does a citizen of Guyana require visa for entering Vietnam or not ?

If you are a Guyana citizen, you are positively required to have visa with your Guyanese passport for entering Vietnam.  Guyana is not among those countries, where you find free visa. Still you may search out thoroughly to confirm whether Guyana is visa free or not. Nevertheless, you must know that, Guyana yet does not have any consulates or embassies. Thus, the passport holders of Guyana has to apply for visa approval letter online and then pick up visa on arrival of international airport of Vietnam. 

There are few countries, where the citizen do not require visa to enter Vietnam. Such as, Norway, Sweden, Russia, Finland, Japan get visa free for exactly 15days but if they need to stay more than 15 days they require visa in that case. In this situation, you must note, if you are planning to stay more than 30 days, then return and come again with your visa free policy.