diff --git a/usr.sbin/bsdinstall/bsdinstall.8 b/usr.sbin/bsdinstall/bsdinstall.8
--- a/usr.sbin/bsdinstall/bsdinstall.8
+++ b/usr.sbin/bsdinstall/bsdinstall.8
@@ -343,6 +343,15 @@
 If this directory does not already exist, it will be created.
 Default:
 .Dq Pa $TMPDIR/bsdinstall_boot
+.It Ev ROOTPASS_ENC
+Encrypted string to set the root password to in the format expected by
+.Xr pw 8
+.Fl H Ar 0 .
+This option is used if both it and
+.Ev ROOTPASS_PLAIN
+are set.
+.It Ev ROOTPASS_PLAIN
+Plain text string to set the root password to.
 .It Ev ZFSBOOT_POOL_NAME
 Name for the pool containing the base system.
 Default:
diff --git a/usr.sbin/bsdinstall/scripts/rootpass b/usr.sbin/bsdinstall/scripts/rootpass
--- a/usr.sbin/bsdinstall/scripts/rootpass
+++ b/usr.sbin/bsdinstall/scripts/rootpass
@@ -33,7 +33,13 @@
 echo "========================"
 echo
 
-echo "Please select a password for the system management account (root):"
-echo "Typed characters will not be visible."
+if [ -n "$ROOTPASS_ENC" ]; then
+	printf '%s\n' "$ROOTPASS_ENC" | pw -R $BSDINSTALL_CHROOT usermod root -H 0
+elif [ -n "$ROOTPASS_PLAIN" ]; then
+	printf '%s\n' "$ROOTPASS_PLAIN" | pw -R $BSDINSTALL_CHROOT usermod root -h 0
+else
+	echo "Please select a password for the system management account (root):"
+	echo "Typed characters will not be visible."
 
-chroot $BSDINSTALL_CHROOT passwd root 2>&1
+	chroot $BSDINSTALL_CHROOT passwd root 2>&1
+fi