diff --git a/usr.bin/truss/main.c b/usr.bin/truss/main.c
index d1a236a7992a..0a31993fa1e6 100644
--- a/usr.bin/truss/main.c
+++ b/usr.bin/truss/main.c
@@ -67,8 +67,8 @@ static __inline void
 usage(void)
 {
   fprintf(stderr, "%s\n%s\n",
-	"usage: truss [-fS] [-o file] -p pid",
-	"       truss [-fS] [-o file] command [args]");
+	"usage: truss [-fdDS] [-o file] -p pid",
+	"       truss [-fdDS] [-o file] command [args]");
   exit(1);
 }
 
@@ -145,7 +145,7 @@ main(int ac, char **av) {
   bzero(trussinfo, sizeof(struct trussinfo));
   trussinfo->outfile = stderr;
 
-  while ((c = getopt(ac, av, "p:o:fS")) != -1) {
+  while ((c = getopt(ac, av, "p:o:fdDS")) != -1) {
     switch (c) {
     case 'p':	/* specified pid */
       trussinfo->pid = atoi(optarg);
@@ -153,6 +153,12 @@ main(int ac, char **av) {
     case 'f': /* Follow fork()'s */
       trussinfo->flags |= FOLLOWFORKS;
       break;
+    case 'd': /* Absolute timestamps */
+      trussinfo->flags |= ABSOLUTETIMESTAMPS;
+      break;
+    case 'D': /* Relative timestamps */
+      trussinfo->flags |= RELATIVETIMESTAMPS;
+      break;
     case 'o':	/* Specified output file */
       fname = optarg;
       break;
@@ -215,6 +221,8 @@ START_TRACE:
    * All of the grunt work is done in the support routines.
    */
 
+  gettimeofday(&trussinfo->start_time, (struct timezone *)NULL);
+
   do {
     int val = 0;
 
@@ -224,8 +232,10 @@ START_TRACE:
       switch(i = pfs.why) {
       case S_SCE:
 	funcs->enter_syscall(trussinfo, pfs.val);
+	gettimeofday(&trussinfo->before, (struct timezone *)NULL);
 	break;
       case S_SCX:
+	gettimeofday(&trussinfo->after, (struct timezone *)NULL);
 	/*
 	 * This is so we don't get two messages for an exec -- one
 	 * for the S_EXEC, and one for the syscall exit.  It also,
diff --git a/usr.bin/truss/syscalls.c b/usr.bin/truss/syscalls.c
index 8056aa122270..1ad7fe1b14f7 100644
--- a/usr.bin/truss/syscalls.c
+++ b/usr.bin/truss/syscalls.c
@@ -40,6 +40,7 @@ static const char rcsid[] =
  */
 
 #include <sys/types.h>
+#include <sys/time.h>
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <netinet/in.h>
@@ -358,9 +359,27 @@ print_syscall(struct trussinfo *trussinfo, const char *name, int nargs, char **s
   int i;
   int len = 0;
 
+  struct timeval timediff;
+
   if (trussinfo->flags & FOLLOWFORKS)
     len += fprintf(trussinfo->outfile, "%5d:  ", trussinfo->pid);
 
+  if (!strcmp(name, "execve") || !strcmp(name, "exit")) {
+    gettimeofday(&trussinfo->after, (struct timezone *)NULL);
+  }
+
+  if (trussinfo->flags & ABSOLUTETIMESTAMPS) {
+    timersub(&trussinfo->after, &trussinfo->start_time, &timediff);
+    len += fprintf(trussinfo->outfile, "%d.%0.7d ",
+		   timediff.tv_sec, timediff.tv_usec);
+  }
+
+  if (trussinfo->flags & RELATIVETIMESTAMPS) {
+    timersub(&trussinfo->after, &trussinfo->before, &timediff);
+    len += fprintf(trussinfo->outfile, "%d.%0.7d ",
+		   timediff.tv_sec, timediff.tv_usec);
+  }
+
   len += fprintf(trussinfo->outfile, "%s(", name);
 
   for (i = 0; i < nargs; i++) {
diff --git a/usr.bin/truss/truss.1 b/usr.bin/truss/truss.1
index 58f9ac53d820..d4cbb6acfd30 100644
--- a/usr.bin/truss/truss.1
+++ b/usr.bin/truss/truss.1
@@ -8,11 +8,11 @@
 .Nd trace system calls
 .Sh SYNOPSIS
 .Nm
-.Op Fl fS
+.Op Fl fdDS
 .Op Fl o Ar file
 .Fl p Ar pid
 .Nm
-.Op Fl fS
+.Op Fl fdDS
 .Op Fl o Ar file
 command
 .Op args
@@ -29,6 +29,12 @@ The options are as follows:
 .It Fl f
 Trace decendants of the original traced process created by fork(),
 vfork, etc.
+.It Fl d
+Include timestamps in the output showing the time elapsed
+since the trace was started.
+.It Fl D
+Include timestamps in the output showing the time elapsed
+since the last recorded event.
 .It Fl S
 Do not display information about signals received by the process.
 (Normally,
diff --git a/usr.bin/truss/truss.h b/usr.bin/truss/truss.h
index f77202aec264..2bb5c8566e09 100644
--- a/usr.bin/truss/truss.h
+++ b/usr.bin/truss/truss.h
@@ -26,6 +26,8 @@
  */
 
 #define FOLLOWFORKS        0x00000001
+#define RELATIVETIMESTAMPS 0x00000002
+#define ABSOLUTETIMESTAMPS 0x00000004
 #define NOSIGS             0x00000008
 
 struct trussinfo
@@ -34,4 +36,8 @@ struct trussinfo
 	int flags;
 	int in_fork;
 	FILE *outfile;
+
+	struct timeval start_time;
+	struct timeval before;
+	struct timeval after;
 };