Mohs surgery usually takes several hours , but the exact length of your appointment depends on how many stages are needed and how the wound is repaired afterwards. Understanding where the time goes can help you prepare for the day and avoid feeling worried if treatment takes longer than expected.

How Long Does the Procedure Usually Take?

For many patients, Mohs surgery takes around two to four hours. Dr Arif Aslam's patient guidance explains that each stage can take approximately one hour once tissue processing and microscopic examination are included, although more complex cases may take longer.

It is sensitive to keep the whole day free. The British Association of Dermatologists describes Mohs as taking around half a day on average, but advises that patients could remain in hospital for most or all of the day depending on how many stages are required.

The length of the appointment does not necessarily mean you will spend several hours having surgery. Much of the time is actually spent waiting while your tissue is prepared and examined under a microscope.

You normally remain awake because the procedure is carried out under local anaesthetic. This means the treatment area is numb, but you are able to rest, read, use your phone or have something to eat during suitable waiting periods.

Why Does Mohs Surgery Take Several Hours?

Mohs surgery works differently from a standard skin cancer excision. The surgeon first removes the visible tumor together with a thin layer of surrounding tissue. That tissue is then carefully processed, mapped and examined to see whether cancer cells remain at any of the margins.

If the margins are clear, no more cancer needs to be removed. If cancer cells remain, the surgeon removes another thin layer only from the affected area and repeats the microscopic examination.

This staged process is what makes Mohs precise, but it also explains why the appointment cannot be given an exact finishing time in advance.

According to the British Association of Dermatologists, around 90% of skin cancers treated with Mohs are cleared within one or two stages. Some cancers need additional stages, particularly when their true borders extend further than they appeared to on the surface.

The laboratory work between stages often takes longer than removing the tissue itself. Dr Arif Aslam's guidance notes that the surgical part of each stage is usually quick and that the waiting periods for tissue analysis account for much of the appointment.

What Can Make Your Appointment Longer?

The number of stages is the biggest factor affecting how long Mohs surgery takes. A tumor that clears after the first stage will generally take less time than one requiring two, three or more rounds of removal and microscopic checking.

Cancer itself can influence this. Mohs is often recommended for cancers with difficult-to-see borders, recurrent tumors, larger cancers and lesions in areas such as the eyelids, nose, ears and lips where preserving healthy tissue is particularly important.

Wound reconstruction also adds time to the appointment. Once the surgeon confirms that the margins are clear, the wound may be closed directly with stitches, reconstructed with a skin flap or graft, or occasionally left to heal naturally.

A straightforward closure may be relatively quick. A larger or more delicate facial reconstruction can take longer because the surgeon must carefully plan the repair to protect both function and appearance.

In some cases, another surgical specialist may become involved in reconstruction. Your team should explain beforehand if this is expected and whether it changes how your treatment day will be organized.

How Should You Prepare for a Long Mohs Appointment?

Because the finishing time cannot always be predicted, avoid making work or social commitments for later that day. Cancer Research UK advises that patients having Mohs may be in hospital for the entire day, even though they normally return home afterwards.

Wear comfortable clothes and bring something to occupy yourself during the waiting periods. The British Association of Dermatologists also advises patients that they can normally eat and drink on the day unless their medical team has given different instructions.

You should also arrange your journey home in advance . Current BAD guidance advises having someone drive you to and from surgery, as driving and public transport are not recommended immediately afterwards.

So, how long does Mohs surgery take? A typical procedure may last around two to four hours, but you should prepare for at least half a day and potentially longer if several stages or complex reconstruction are needed.

If you are preparing for Mohs surgery, contact Dr Arif Aslam's team to discuss your individual treatment plan, expected appointment length and what you should bring on the day.