HOWTO integrate NASM with VS2019

updated 18/04/2023

Occasionally I use Intel assembler language to squeeze processing power from my programs.

A cheap solution was C inline assembler sections, but VS2019 doesn’t support them in a 64-bits program.  Other compilers use other more or less complex solutions (IBM assembler, …).

This forced me to consider having & link .asm files in my projects.  I can split them with 32 and 64 bits code and compile them when needed.  Then I tried to use MASM included in Visual Studio… but I found it really complex to use, and quite poorly documented.

So I started to consider using NASM, an open-source assembler compiler, simpler and much better documented.

Download and Installation

The first step is to download and install the following needed pieces.

then install the first file (for example into “c:\nasm” folder) and copy VSNASM files in the same folder.

The last thing is to define 2 different environmental variables with the installation folder:

  • NASMPATH with the final ‘\‘ (“c:\nasm\” in our example).
  • NASMPATH_VS without the final ‘\‘ (“c:\nasm” in our example).

NOTE1: I warmly suggest installing it, in the ‘program files‘ folder to keep them safer.

NOTE2: I also warmly suggest editing ‘nasm.xml‘ to change the DisplayName to “NASM – Netwide Assembler” into the following nodes at the end of the file:

  • ItemType
  • ContentType

Setting up Visual Studio

Start Visual Studio and:

  • open ‘Tools‘->’Options…‘ window from the main menu.
  • go to ‘Projects and Solutions‘ -> ‘VC++ Project Settings‘.
  • add ‘$(NASMPATH_VS)‘ to ‘Build Customization Search Path‘.
  • confirm and exit.

Once installed, it can be configured for Nasm Intel Syntax highlighting from VS options.

If using VS2019, even if it is not mandatory, I suggest also installing ‘AsmDude‘ extension for syntax highlighting into .asm files.

VS Project Setup

The last step is to enable .asm support in your project.

  • open your project.
  • right-click each project using .asm files.
  • select ‘Build Dependencies‘->’Build Customizations‘.
  • check ‘nasm‘ option.
  • confirm.

Then for each .asm file, you have to:

  • open the file ‘Properties
  • set into ‘General‘->’Item Type‘ to ‘Netwide Assembler‘ (or whatever you set, “NASM – Netwide Assembler” in my case).
  • enable the debug information for the debug profile from the specific NASM options.
  • confirm.

NOTE: from this last property window, we can also set if to compile the file or not in 32/64 bits target platforms.


After all these steps, we can start with something like:

bits 32

section .data
<put your data here>

section .text
<put your function here>

Have fun