Find out the device name of the USB stick

The device name should be something like /dev/disk8, /dev/disk9, etc.

If you are not sure about the exact device name, do the following:

Unplug the USB stick.
Open Terminal from Applications ▸ Utilities ▸ Terminal.app
Execute the following command:
```
 diskutil list
```
This returns a list of all the current storage devices. For example:

$ diskutil list
/dev/disk0
    #:                       TYPE NAME                 SIZE       IDENTIFIER
    0:      GUID_partition_scheme                     *500.1 GB   disk0
    1:                        EFI                      209.7 MB   disk0s1
    2:                  Apple_HFS MacDrive             250.0 GB   disk0s2
    3:                        EFI                      134.1 GB   disk0s3
    4:       Microsoft Basic Data BOOTCAMP             115.5 GB   disk0s4

Plug back the USB stick and run the same command as before:
```
 diskutil list
```
A new device should appear in the list of storage devices. Check that the size of the device corresponds to the size of your USB stick.

$ diskutil list
/dev/disk0
   #:                       TYPE NAME                 SIZE       IDENTIFIER
   0:      GUID_partition_scheme                     *500.1 GB   disk0
   1:                        EFI                      209.7 MB   disk0s1
   2:                  Apple_HFS MacDrive             250.0 GB   disk0s2
   3:                        EFI                      134.1 GB   disk0s3
   4:       Microsoft Basic Data BOOTCAMP             115.5 GB   disk0s4
/dev/disk1
   #:                       TYPE NAME                 SIZE       IDENTIFIER
   0:     FDisk_partition_scheme                     *4.0 GB     disk1
   1:                  Apple_HFS Untitled 1           4.0 GB     disk1s1

In this example, the USB stick is 4.0 GB and the device name is /dev/disk1. Yours are probably different.

If you are not sure about the device name you should stop proceeding or you risk overwriting any hard drive on the system.

Unmount the USB drive

Execute the following command, replacing [device] with the device name found in step 1.

 diskutil unmountDisk [device]

Run isohybrid.pl on the ISO image

You need to modify the ISO image using isohybrid before copying it onto the USB stick.

Download syslinux.
Double click on the package to extract it.
Copy isohybrid.pl from the /utils folder to the desktop.
Copy the ISO image (for example tails-i386-0.17.1.iso) to the desktop.
To change directory into the desktop, execute:
```
cd Desktop
```
To run isohybrid.pl on the ISO image, execute the following command, replacing [tails.iso] with the path to the ISO image that you want to install.
```
perl isohybrid.pl [tails.iso]
```
Here is an example of the commands to execute, yours are probably different:
```
perl isohybrid.pl tails-i386-0.17.1.iso
```

If you are not sure about the path to the ISO image or if you get a No such file or directory error, you can first type `perl isohybrid.pl`, followed by a space, and then drag and drop the icon of the ISO image from a file browser onto Terminal. This should insert the correct path to the ISO image in Terminal. Then complete the command and execute it.

Do the copy

Execute the following command, replacing [tails.iso] by the path to the ISO image that you want to copy and [device] by the device name found in step 1.

dd if=[tails.iso] of=[device]

You should get something like this:

dd if=tails-0.17.1.iso of=/dev/disk9

If you don't see any error message, Tails is being copied onto the USB stick. The whole process might take some time, generally a few minutes.

If you get a "Permission denied" error, try executing the command with sudo:

sudo dd if=[tails.iso] of=[device]

Be careful, if the device name is wrong you might overwriting any hard drive on the system.

The installation is complete when the command prompt reappears.

Setup rEFInd

To start Tails from that USB stick, you need to have rEFInd installed on the Mac.

If you need help with rEFInd, look at their installation documentation.

rEFInd will replace your original bootloader.
This could cause your Mac to not boot. It is recommended to create a full backup and know how to restore. See Apple's instructions.

Notes

This method was successfully tested on the following hardware:

MacBook Pro Model A1150 with OS X 10.6.8, 2006
MacBook Pro Retina 15" Mid-2012 (aka MacBookPro10,1)

The method worked on some hardware but a bug in the video support prevented Tails to start successfully:

MacBook Pro Retina with OS X 10.8.3, December 2012
Macbook Pro model A1150

Note that Tails developers are in general not very knowledgeable about Mac. Any additional information is welcome.